CN110023796B

CN110023796B - Wavelength conversion member and backlight unit

Info

Publication number: CN110023796B
Application number: CN201780074328.XA
Authority: CN
Inventors: 米本隆
Original assignee: Fujifilm Corp
Current assignee: Fujifilm Corp
Priority date: 2016-11-30
Filing date: 2017-11-29
Publication date: 2021-10-08
Anticipated expiration: 2037-11-29
Also published as: CN110023796A; JP6785316B2; US20190292453A1; US10781369B2; JPWO2018101348A1; WO2018101348A1

Abstract

The invention provides a wavelength conversion member and a backlight unit having high reproducibility of white light in the wavelength conversion member containing a phosphor such as a quantum dot. The wavelength conversion member includes: a resin layer having a plurality of recesses discretely arranged on one main surface side; and a wavelength conversion layer having a plurality of fluorescent regions including a phosphor, the phosphor being disposed in a recess formed in the resin layer, and a surface roughness Ra of a surface of the resin layer on a side where the recess is formed being 0.3 to 5 [ mu ] m.

Description

Wavelength conversion member and backlight unit

Technical Field

The present invention relates to a wavelength conversion member including a phosphor that emits fluorescence when irradiated with excitation light, and a backlight unit including the wavelength conversion member.

Background

Flat panel displays such as Liquid Crystal Displays (LCDs) are used as image Display devices which consume less power and save space, and their applications are expanding year by year. In recent years, liquid crystal display devices are required to have further improved LCD performance, such as power saving and color reproducibility.

With the power saving of the backlight of the LCD, in order to improve the light utilization efficiency and to improve the color reproducibility, it has been proposed to use a wavelength conversion member having a wavelength conversion layer containing quantum dots (also referred to as QuantumDot, QD.) emitted by converting the wavelength of incident light as a light emitting material (phosphor).

The quantum dot is a state in which electrons are restricted in the movement direction in all directions in three dimensions, and when a semiconductor nanoparticle is three-dimensionally surrounded by a high barrier, the nanoparticle becomes a quantum dot. Quantum dots exhibit various quantum effects. For example, a "quantum size effect" in which the state density (energy level) of electrons is discretized is exhibited. By changing the size of the quantum dot according to the quantum size effect, the absorption wavelength or emission wavelength of light can be controlled.

In general, such quantum dots are dispersed in a resin or the like, and are used, for example, as a wavelength conversion member for performing wavelength conversion, disposed between a backlight and a liquid crystal panel.

When excitation light enters the wavelength conversion member including the quantum dots from the backlight, the quantum dots are excited to emit fluorescent light. Here, by using quantum dots having different emission characteristics and causing each quantum dot to emit light having a narrow half-width of red light, green light, or blue light, white light can be realized. Alternatively, white light can be realized by the excitation light transmitted through the wavelength conversion member and the light emission of the quantum dots by using the quantum dots emitting yellow light with the excitation light being blue light.

Since the half-width of fluorescence by quantum dots is narrow, white light obtained by appropriately selecting the wavelength can be designed to have high luminance and excellent color reproducibility.

For example, patent document 1 describes an optical module including: a substrate having one or more recesses; and one or more compositions disposed in the recess and comprising a plurality of luminescent nanocrystals.

Prior art documents

Patent document

Patent document 1: U.S. patent publication No. 2014/178648

Disclosure of Invention

Technical problem to be solved by the invention

Further thinning is required for flat panel displays such as LCDs, and further thinning is also required for wavelength conversion members used for the flat panel displays.

As a result of the studies by the present inventors, it has been found that when the wavelength conversion member (wavelength conversion layer) is made thin, the content of the phosphor in the wavelength conversion layer decreases, and therefore, the amount of light emitted from the phosphor decreases, which causes a problem of a decrease in color reproducibility. Further, it is found that when the wavelength conversion layer is made thin, the influence of the in-plane thickness unevenness is increased, and therefore, there arises a problem that the amount of fluorescence emission varies depending on the position, and color reproducibility is lowered.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a wavelength conversion member having high color reproducibility in a wavelength conversion member containing a phosphor such as a quantum dot, and a backlight unit including the wavelength conversion member.

Means for solving the technical problem

The present inventors have intensively studied to achieve the above object, and as a result, have found that the above object can be solved by the following means, and have completed the present invention: a wavelength conversion member that absorbs at least a part of incident excitation light, converts the absorbed excitation light into light having a wavelength different from that of the excitation light, and emits the converted light, the wavelength conversion member comprising a wavelength conversion layer that comprises: a resin layer having a plurality of recesses discretely arranged on one main surface side; and a plurality of fluorescent regions containing fluorescent material, which are arranged in the concave portions formed on the resin layer, wherein the surface roughness Ra of the surface of the resin layer on the side where the concave portions are formed is 0.3-5 μm.

That is, the following configuration was found to achieve the above-described object.

(1) A wavelength conversion element which absorbs at least a part of incident excitation light and converts the absorbed excitation light into light having a wavelength different from that of the excitation light for emission,

the wavelength conversion member has a wavelength conversion layer having: a resin layer having a plurality of recesses discretely arranged on one main surface side; and a plurality of fluorescent regions containing a fluorescent material, which are arranged in the concave portion formed on the resin layer,

The surface roughness Ra of the surface of the resin layer on the side where the recess is formed is 0.3 to 5 [ mu ] m.

(2) The wavelength conversion member according to item (1), wherein a refractive index difference Δ n between the resin layer and the fluorescent region is 0.05 or more.

(3) The wavelength conversion member according to (1) or (2), wherein at least one of the resin layer and the fluorescent region contains scattering particles.

(4) The wavelength conversion member according to any one of (1) to (3), wherein a depth of the recess formed in the resin layer is 1 to 150 μm.

(5) The wavelength conversion member according to any one of (1) to (4), wherein a width of the recess formed in the resin layer is 10 to 2000 μm.

(6) The wavelength conversion member according to any one of (1) to (5), wherein the wavelength conversion layer has two or more kinds of fluorescent regions that emit light in different wavelength ranges.

(7) The wavelength converting member according to any one of (1) to (6), which has two substrate films laminated with a wavelength converting layer interposed therebetween.

(8) The wavelength conversion member according to any one of (1) to (7), wherein the wavelength conversion layer has a thickness of 5 to 150 μm.

(9) A backlight unit, having: (1) the wavelength converting member according to any one of (1) to (8); and a light source for emitting excitation light.

Effects of the invention

According to the present invention, a wavelength conversion member having high reproducibility of white light in a wavelength conversion member containing a fluorescent material such as a quantum dot, and a backlight unit including the wavelength conversion member can be provided.

Drawings

Fig. 1 is a perspective view schematically showing an example of a wavelength conversion member according to the present invention.

Fig. 2 is a top view of the wavelength conversion member of fig. 1.

Fig. 3 is a cross-sectional view of the wavelength conversion member of fig. 1.

Fig. 4 is a partially enlarged cross-sectional view schematically showing a boundary between the resin layer and the fluorescent region.

Fig. 5 is a plan view showing another example of the plan pattern of the fluorescent region.

Fig. 6 is a plan view showing another example of the plan pattern of the fluorescent region.

Fig. 7 is a diagram for explaining a method of determining the profile of the fluorescence region.

Fig. 8 is a schematic diagram for explaining a method of manufacturing a wavelength conversion member according to the present invention.

Fig. 9 is a schematic diagram for explaining a method of manufacturing a wavelength conversion member according to the present invention.

Fig. 10 is a schematic structural cross-sectional view of a backlight unit including a wavelength conversion member.

Detailed Description

Hereinafter, embodiments of a wavelength conversion member and a backlight unit including the wavelength conversion member according to the present invention will be described with reference to the drawings. In the drawings of the present specification, the scale of each portion is appropriately changed for easy recognition. In the present specification, the numerical range expressed by the term "to" means a range including numerical values before and after the term "to" as a lower limit value and an upper limit value.

In the present specification, "(meth) acrylate" is used in the meaning of at least one or both of acrylate and methacrylate. "(meth) acryloyl group", and the like are also the same.

< wavelength conversion element >

The wavelength conversion member of the present invention is a wavelength conversion member comprising: which absorbs at least a part of incident excitation light and converts the absorbed excitation light into light having a wavelength different from that of the excitation light, and emits the converted light,

Fig. 1 is a perspective view schematically showing an example of a wavelength conversion member 1 according to the present invention, fig. 2 is a plan view of fig. 1, and fig. 3 is a cross-sectional view of fig. 1. In fig. 1, for the sake of explanation, the 2 nd base material film 20 is shown by a broken line, and the wavelength conversion layer 30 is shown by a solid line.

The wavelength conversion member 1 of the present embodiment includes: 1 st substrate film 10; a wavelength conversion layer 30 in which a plurality of regions 35 containing phosphors 31 that emit fluorescence when excited by excitation light are discretely arranged on the 1 st base material film 10, and a resin layer 38 is arranged between the discretely arranged regions 35 containing the phosphors 31; and a 2 nd base material film 20 disposed on the wavelength conversion layer 30. Hereinafter, the region 35 including the fluorescent material 31 is referred to as a fluorescent region 35.

In other words, the wavelength conversion layer 30 has the following structure: the fluorescent screen includes a resin layer 38 and a fluorescent area 35, a plurality of recesses are discretely formed in the resin layer 38, and the fluorescent area 35 is disposed in the recesses of the resin layer 38.

In the present specification, "a plurality of regions containing … … phosphors are discretely arranged on the 1 st substrate film" means that, as shown in fig. 1 and 2, a plurality of fluorescent regions 35 are arranged so as to be isolated from each other in a two-dimensional direction along the film surface of the 1 st substrate film 10 when viewed from a direction perpendicular to the film surface of the 1 st substrate film (in a plan view). In the example shown in fig. 1, the fluorescent regions 35 are columnar (disk-shaped), are surrounded by the resin layer 38 in the two-dimensional direction along the film surface of the 1 st base material film 10, and are isolated from each other, and the entry of oxygen into the respective fluorescent regions 35 from the two-dimensional direction along the film surface of the 1 st base material film 10 is blocked.

As shown in fig. 3, the fluorescent regions 35 may be disposed in a plurality of concave portions of the resin layer 38 and formed so as to cover upper portions of the uneven surface of the resin layer 38. That is, the portions of the fluorescence region 35 independently disposed in each recess may be locally connected.

In the wavelength conversion member of the present invention, the surface roughness Ra of the surface of the resin layer on the side where the concave portion is formed is 0.3 to 5 μm. That is, the surface roughness Ra of the surface of the resin layer in contact with the fluorescent region is 0.3 to 5 μm.

As described above, further thinning is required for flat panel displays such as LCDs, and further thinning is also required for wavelength conversion members used for the flat panel displays.

However, according to the studies by the present inventors, it has been found that when the wavelength conversion member (wavelength conversion layer) is made thin, the content of the phosphor in the wavelength conversion layer decreases, and thus the amount of light emitted from the phosphor decreases, which causes a problem of a decrease in color reproducibility. For example, when white light is realized using quantum dots that emit yellow light with excitation light of blue light, white light is realized by balancing the amounts of excitation light (blue light) that has passed through the wavelength conversion member and fluorescent light (yellow light) emitted by the quantum dots.

Further, it is known that when the wavelength conversion layer is made thin, the influence of the in-plane thickness unevenness is increased, and thus the amount of fluorescence emission differs depending on the position, which causes a problem of a decrease in color reproducibility. For example, when white light is realized using 3 kinds of quantum dots that emit red light, green light, and blue light, respectively, if the light emission amounts differ depending on the positions, the balance of the light amounts of the red light, the green light, and the blue light is lost, and the white light cannot be reproduced accurately.

In contrast, in the wavelength conversion member of the present invention, the wavelength conversion layer includes a resin layer having a plurality of recesses formed therein and a fluorescent region including a phosphor, the fluorescent region is disposed in the plurality of recesses, and a surface roughness Ra of a surface of the resin layer on the recess side is 0.3 to 5 μm.

By disposing the fluorescent regions in the plurality of recesses formed in the resin layer, even if the wavelength conversion layer is made thin, the fluorescent regions can be formed to have a uniform thickness, and a decrease in color reproducibility due to variations in thickness can be suppressed.

Further, by setting the surface roughness Ra of the surface of the resin layer on the side where the recess is formed to be 0.3 to 5 μm, the fluorescence emitted from the fluorescent material in the fluorescent region can be scattered, and the amount of fluorescence emitted from the main surface of the wavelength conversion member can be increased, thereby suppressing a decrease in color reproducibility due to a shortage of the amount of fluorescence.

Here, in a structure in which only the fluorescent region is a flat layer and the surface of the member adjacent thereto is roughened to scatter light, the fluorescent light cannot be sufficiently scattered. On the other hand, by forming the recess in the resin layer and roughening the surface of the recess at an angle different from the surface of the wavelength conversion member, such as the side surface of the recess, with the surface roughness Ra of 0.3 to 5 μm, it is possible to more appropriately scatter the fluorescence from the fluorescent material emitted in various directions and increase the amount of fluorescence emitted from the main surface of the wavelength conversion member.

For example, in a structure in which the fluorescent region is a flat layer and the surface of the member adjacent to the flat layer is roughened, it is difficult to sufficiently scatter the fluorescent light traveling in the direction substantially parallel to the surface of the wavelength conversion member. In contrast, in the structure in which the concave portion is formed in the resin layer and the surface thereof is roughened, since the fluorescence traveling in the direction substantially parallel to the surface of the wavelength conversion member can be easily scattered, the fluorescence traveling in the direction substantially parallel to the surface of the wavelength conversion member can be guided in the direction substantially perpendicular to the surface of the wavelength conversion member, and the amount of the fluorescence emitted from the main surface side of the wavelength conversion member can be increased.

Further, by roughening the surface on which the plurality of concave portions are formed, the substantial surface area of the roughened surface can be increased, and the scattering effect by the roughening can be further improved.

The surface roughness Ra of the surface of the resin layer on the side where the recessed portion is formed is preferably 0.5 to 2 μm, and more preferably 0.6 to 1.5 μm.

The surface roughness Ra of the resin layer was determined by cutting the wavelength conversion member with a microtome to form a cross section, and observing the cross section with a scanning electron microscope. Specifically, Ra was obtained from the roughness curve of the interface between the resin layer and the phosphor-containing layer in the observed cross section in accordance with JIS B0601. The evaluation length was set to 50 μm, and an average value of n-5 was used.

However, when the width of the adjacent fluorescence region 35, that is, the thickness t of the resin layer 38 is smaller than 50 μm, the evaluation length in calculating Ra is set to be equal to t.

The surface of the resin layer on the side where the recesses are formed may be roughened randomly, or may be roughened by forming minute protrusions in a predetermined pattern, as shown in fig. 4.

Further, only a part of the bottom surface of the recess, the top surface of the projection, the slope from the bottom surface to the top surface, and the like of the resin layer may be roughened.

Here, in the present invention, the difference Δ n between the refractive index of the resin layer 38 and the refractive index of the fluorescent region 35 is preferably 0.05 or more, more preferably 0.1 or more, and further preferably 0.4 or more and 2.0 or less.

By setting the refractive index difference Δ n between the resin layer 38 and the fluorescent region to the above range, the light emission from the fluorescent region 35 can be more appropriately scattered.

In the wavelength conversion member of the present invention, when the depth of the recess of the resin layer 38 in which the fluorescent regions 35 are arranged is h and the width between adjacent fluorescent regions 35, that is, the thickness of the resin layer 38 is t, the depth h of the recess of the resin layer 38 is preferably 1 μm or more and 150 μm or less, the width t between adjacent fluorescent regions 35 is preferably 5 μm or more and 300 μm or less, and the aspect ratio h/t between the width t and the depth h between adjacent fluorescent regions 35 is preferably less than 3.0.

The width of the recess, i.e., the width of the fluorescent region, is preferably 10 μm or more and 2000 μm or less.

By setting the depth h of the recess of the resin layer 38 to be 1 μm or more and 100 μm or less, variation in the in-plane thickness of the fluorescent region 35 can be appropriately suppressed, and the scattering effect by roughening can be appropriately obtained.

Further, the light quantity of the phosphor can be secured by setting the width of the recess to 10 μm or more and 2000 μm or less.

Further, by setting the width t between the adjacent fluorescent regions 35 to be 5 μm or more and 300 μm or less, it is possible to suppress the resin layer from being visually recognized, and it is possible to appropriately suppress variation in the in-plane thickness of the fluorescent regions 35 while securing the strength of the resin layer having a plurality of concave portions. Further, the scattering effect by the roughening can be obtained appropriately.

Further, by setting the aspect ratio h/t of the width t and the depth h between the adjacent fluorescent regions 35 to be less than 3.0, it is possible to appropriately suppress variation in the in-plane thickness of the fluorescent regions 35 while securing the strength of the resin layer.

The depth h of the recess formed in the resin layer 38 is determined as follows: the depressed portions of the wavelength conversion member were cut with a microtome to form a cross section, the cross section was observed with a confocal laser microscope in a state where the wavelength conversion layer was irradiated with excitation light to emit light from the phosphor, and 10 depressed portions were extracted to measure the depth, and the depth was determined as an average value.

The width t between the adjacent fluorescent regions 35 (the thickness t of the resin layer 38 portion) is the shortest distance between the adjacent fluorescent regions 35 on the center coordinate in the thickness direction (the middle between the convex portion and the concave portion of the resin layer 38), and the surface is observed from one surface of the wavelength conversion member using a confocal laser microscope in a state where the excitation light is irradiated to the wavelength conversion layer and the phosphor is caused to emit light, and the width of the resin layer 38 portion between at least 20 adjacent fluorescent regions 35 is extracted and read, and the average value of these is calculated as the width t.

The width of the recess is the length of the maximum width of the opening surface of the recess. For example, if the opening surface of the recess is circular, the width of the recess is the diameter, and if the opening surface of the recess is rectangular, the width of the recess is the length of the diagonal line.

The widths of the recesses were calculated by extracting at least 20 recesses from the surface of the wavelength conversion member observed from one surface thereof using a confocal laser microscope in a state where the phosphor was caused to emit light by irradiating the wavelength conversion layer with excitation light, and reading the widths, and calculating the average value of the widths as the width of the recess.

In the example shown in fig. 1, the shape of the recess of the resin layer 38, that is, the shape of the fluorescent area 35 is a cylindrical shape and a circular shape in plan view, but the shape of the fluorescent area 35 is not particularly limited. As shown in fig. 5, the phosphor regions 35 may be polygonal prisms or regular polygonal prisms, such as quadrangular in plan view or hexagonal in plan view as shown in fig. 6. In the above examples, the bottom surface of the column or the polygonal column is arranged parallel to the substrate film surface, but the bottom surface may not necessarily be arranged parallel to the substrate film surface. Further, the shape of each fluorescent region 35 may be irregular.

When the boundary of the resin layer 38 between the binder 33 and the fluorescent region 35 in the fluorescent region 35 is not clear, as shown in fig. 7, a line connecting points located on the outer side (the side where the fluorescent material 31 is not arranged) of the fluorescent body 31e located near the outermost portion of the region where the fluorescent body 31 is arranged is regarded as the outline (the boundary between the fluorescent region 35 and the resin layer 38) m of the fluorescent region 35. By irradiating the wavelength conversion layer with excitation light and causing the phosphor to emit light and observing the phosphor with a confocal laser microscope or the like, for example, the position of the phosphor can be specified, and the profile m of the fluorescence region 35 can be specified. In this specification, the sides of the cylinder or polygon are allowed to meander like the profile of fig. 7.

Further, although the fluorescent regions 35 are arranged in a periodic pattern in the above embodiment, if a plurality of fluorescent regions 35 are arranged discretely, they may be aperiodic as long as desired performance is not impaired. When the fluorescent regions 35 are uniformly distributed over the entire wavelength conversion layer 30, the in-plane distribution of luminance is uniform, which is preferable.

In order to make the amount of fluorescence sufficient, it is preferable to make the region occupied by the fluorescence region 35 as large as possible.

One or more kinds of the phosphors 31 may be contained in the phosphor region 35. Further, one phosphor 31 may be used in the 1 phosphor regions 35, and a region including the 1 st phosphor and a region including the 2 nd phosphor different from the 1 st phosphor among the plurality of phosphor regions 35 may be periodically or non-periodically arranged. The number of the phosphors may be 3 or more.

The wavelength conversion layer 30 may be formed by laminating a plurality of fluorescent regions 35 in the thickness direction of the thin film.

The thickness of the wavelength conversion layer 30 is preferably 5 to 150 μm, and more preferably 5 to 50 μm. By setting the thickness of the wavelength conversion layer 30 within the above range, the thickness of the wavelength conversion member can be reduced, and a decrease in color reproducibility due to an insufficient amount of fluorescent light can be suppressed.

Hereinafter, each constituent element of the wavelength conversion member of the present invention will be described.

The wavelength conversion member 1 has the following structure: a wavelength conversion layer 30 is laminated on one film surface of the 1 st base film 10, and a 2 nd base film 20 is laminated on the wavelength conversion layer 30, and the wavelength conversion layer 30 is sandwiched between the two

base films

10 and 20.

Wavelength conversion layer-

The wavelength conversion layer 30 includes: a resin layer 38 having a plurality of recesses discretely arranged; and a plurality of fluorescent regions 35 including the fluorescent material 31 disposed in the plurality of concave portions formed in the resin layer 38.

< region containing phosphor (fluorescent region) >)

The fluorescent region 35 is composed of a fluorescent material 31 and a binder 33 in which the fluorescent material 31 is dispersed, and is formed by applying a fluorescent region forming coating liquid containing a curable composition composed of the fluorescent material 31 and the binder 33 and curing the coating liquid.

< phosphor >

As the phosphor, various known phosphors can be used. Examples of the fluorescent material include inorganic phosphors such as rare earth doped garnet, silicate, aluminate, phosphate, ceramic phosphor, sulfide phosphor, nitride phosphor, oxynitride phosphor, and fluoride phosphor, and organic phosphors typified by organic fluorescent dyes and organic fluorescent pigments. Further, a phosphor in which a rare earth is doped in semiconductor fine particles and semiconductor nano-particles (quantum dots, quantum rods) can also be preferably used. One kind of the phosphor may be used alone, but in order to obtain a desired fluorescence spectrum, a plurality of kinds of phosphors having different wavelengths may be mixed and used, or a combination of phosphors composed of different materials (for example, a combination of a rare earth-doped garnet and a quantum dot) may be used.

In the following, the phosphor is mainly described by taking quantum dots as an example, but the phosphor of the present invention is not limited to quantum dots, and is not particularly limited as long as it is a material that converts energy from the outside into light or converts light into electricity, such as other fluorescent dye or photoelectric conversion material.

(Quantum dot)

The quantum dot is a fine particle of a compound semiconductor having a size of several nm to several tens of nm, and emits fluorescence when excited by at least incident excitation light.

The phosphor of the present embodiment may include at least one kind of quantum dot, and may include two or more kinds of quantum dots having different emission characteristics. Known quantum dots include quantum dots (a) having an emission center wavelength in a wavelength range of 600nm to 680nm, quantum dots (B) having an emission center wavelength in a wavelength range of 500nm to less than 600nm, and quantum dots (C) having an emission center wavelength in a wavelength range of 400nm to less than 500nm, wherein the quantum dots (a) are excited by excitation light to emit red light, the quantum dots (B) emit green light, and the quantum dots (C) emit blue light. For example, when blue light is incident as excitation light on a wavelength conversion layer including quantum dots (a) and quantum dots (B), white light can be realized by red light emitted from the quantum dots (a), green light emitted from the quantum dots (B), and blue light transmitted through the wavelength conversion layer. Alternatively, by making ultraviolet light incident on the wavelength conversion layer including the quantum dots (a), (B), and (C) as excitation light, white light can be realized by red light emitted from the quantum dot (a), green light emitted from the quantum dot (B), and blue light emitted from the quantum dot (C).

As for the quantum dots, for example, refer to paragraphs 0060 to 0066 of japanese patent application laid-open No. 2012-1699271, but the quantum dots are not limited to those described therein. As the quantum dot, a commercially available product can be used without any limitation. The emission wavelength of the quantum dot can be generally adjusted depending on the composition and size of the particle.

The quantum dots can be added, for example, in an amount of about 0.1 to 10 parts by mass per 100 parts by mass of the total amount of the coating liquid.

The quantum dots may be added to the coating liquid in the form of particles or may be added in the form of a dispersion in an organic solvent. From the viewpoint of suppressing aggregation of the particles of the quantum dots, the addition is preferably in the form of a dispersion. The organic solvent used in the dispersion of the quantum dots is not particularly limited.

As the quantum dot, for example, a core-shell type semiconductor nanoparticle is preferable from the viewpoint of improving durability. As the core, II-VI semiconductor nanoparticles, III-V semiconductor nanoparticles, multi-component semiconductor nanoparticles, and the like can be used. Specific examples thereof include, but are not limited to, CdSe, CdTe, CdS, ZnS, ZnSe, ZnTe, InP, InAs, and InGaP. Among them, CdSe, CdTe, InP, and InGaP are preferable from the viewpoint of efficiently emitting visible light. As the shell, CdS, ZnS, ZnO, GaAs, and a complex thereof can be used, but the shell is not limited thereto. The emission wavelength of the quantum dot can be generally adjusted according to the composition and size of the particle.

The quantum dots may be spherical particles, rod-shaped particles called quantum rods, or tetragonal particles. From the viewpoint of reducing the full width at half maximum (FWHM) of light emission and expanding the color reproduction region of the liquid crystal display device, spherical quantum dots or rod-shaped quantum dots (i.e., quantum rods) are preferable.

A ligand having a coordinating group having lewis basicity may be coordinated on the surface of the quantum dot. Also, quantum dots coordinated with such ligands can be used. Examples of the Lewis basic coordinating group include an amino group, a carboxyl group, a mercapto group, a phosphino group, and the like. Specific examples thereof include hexylamine, decylamine, hexadecylamine, octadecylamine, oleylamine, myristylamine, laurylamine, oleic acid, mercaptopropionic acid, trioctylphosphine, and tri-n-octylphosphine oxide. Among them, hexadecylamine, trioctylphosphine and tri-n-octylphosphine oxide are preferable, and tri-n-octylphosphine oxide is particularly preferable.

The quantum dot coordinated with these ligands can be produced by a known synthesis method. For example, they can be synthesized by The method described in C.B.Murray, D.J.Norris, M.G.Bawendi, Journal American Chemical Society,1993,115(19), pp.8706-8715 or The Journal Physical Chemistry,101, pp.9463-9475, 1997. In addition, as the quantum dot coordinated with the ligand, a commercially available quantum dot can be used without any limitation. For example, Lumidot (manufactured by Sigma-Aldrich Co.) can be given.

In the present invention, the content of the quantum dot to which the ligand is coordinated is preferably 0.01 to 10% by mass, more preferably 0.05 to 5% by mass, based on the total mass of the polymerizable compound contained in the quantum dot-containing composition to be a fluorescent region. The concentration is preferably adjusted according to the thickness of the wavelength conversion member.

The quantum dots may be added to the composition containing quantum dots in the form of particles, or may be added in the form of a dispersion liquid dispersed in a solvent. From the viewpoint of suppressing aggregation of the particles of the quantum dots, the addition is preferably in the form of a dispersion. The solvent used herein is not particularly limited.

(method for synthesizing ligand)

The ligand in the quantum dot-containing composition can be synthesized by a known synthesis method. For example, the synthesis can be carried out by the method described in Japanese patent application laid-open No. 2007-277514.

< curable composition for adhesive for forming fluorescent region >

In the present invention, the curable composition for forming a binder of the fluorescent region preferably contains a polymerizable compound.

(polymerizable Compound)

The polymerizable compound is preferably a propylene-based compound. The monofunctional or polyfunctional (meth) acrylate monomer is preferable, and may be a prepolymer or a polymer of the monomer as long as it has polymerizability. In the present specification, "(meth) acrylate" means either or both of acrylate and methacrylate. "(meth) acryloyl group", and the like are also the same.

-monofunctional compounds- -

Examples of the monofunctional (meth) acrylate monomer include acrylic acid, methacrylic acid, and derivatives thereof, and more specifically, a monomer having 1 polymerizable unsaturated bond ((meth) acryloyl group) of (meth) acrylic acid in the molecule. Specific examples thereof include the following compounds, but the present embodiment is not limited thereto.

Examples thereof include alkyl (meth) acrylates having an alkyl group of 1 to 30 carbon atoms such as methyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isononyl (meth) acrylate, n-octyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, and the like; aralkyl (meth) acrylates having 7 to 20 carbon atoms in an aralkyl group such as benzyl (meth) acrylate; alkoxyalkyl (meth) acrylates having 2 to 30 carbon atoms in an alkoxyalkyl group such as butoxyethyl (meth) acrylate; aminoalkyl (meth) acrylates having a total of 1 to 20 carbon atoms of a (monoalkyl or dialkyl) aminoalkyl group such as N, N-dimethylaminoethyl (meth) acrylate; (meth) acrylates of polyalkylene glycol alkyl ethers having an alkylene chain of 1 to 10 carbon atoms and a terminal alkyl ether of 1 to 10 carbon atoms, such as (meth) acrylate of diethylene glycol ethyl ether, (meth) acrylate of triethylene glycol butyl ether, (meth) acrylate of tetraethylene glycol monomethyl ether, (meth) acrylate of hexamethylene glycol monomethyl ether, (meth) acrylate of octaethylene glycol monomethyl ether, monomethyl ether (meth) acrylate of nonaethylene glycol, monomethyl ether (meth) acrylate of dipropylene glycol, monomethyl ether (meth) acrylate of heptapropylene glycol, and monoethyl ether (meth) acrylate of tetraethylene glycol; a (meth) acrylate of a polyalkylene glycol aryl ether having 1 to 30 carbon atoms in the alkylene chain and 6 to 20 carbon atoms in the terminal aryl ether, such as a (meth) acrylate of hexaethylene glycol phenyl ether; (meth) acrylates having an alicyclic structure and having a total of 4 to 30 carbon atoms, such as cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, isobornyl (meth) acrylate, and cyclododecatriene (meth) acrylate added with formaldehyde (methyl oxide); fluorinated alkyl (meth) acrylates having 4 to 30 total carbon atoms such as heptadecafluorodecyl (meth) acrylate; (meth) acrylates having a hydroxyl group such as 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, triethylene glycol mono (meth) acrylate, tetraethylene glycol mono (meth) acrylate, hexaethylene glycol mono (meth) acrylate, octapropylene glycol mono (meth) acrylate, mono-or di (meth) acrylate of glycerin; glycidyl group-containing (meth) acrylates such as glycidyl (meth) acrylate; polyethylene glycol mono (meth) acrylates having 1 to 30 carbon atoms in the alkylene chain, such as tetraethylene glycol mono (meth) acrylate, hexaethylene glycol mono (meth) acrylate, and octapropylene glycol mono (meth) acrylate; (meth) acrylamides such as (meth) acrylamide, N-dimethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, 2-hydroxyethyl (meth) acrylamide, and acryloylmorpholine.

From the viewpoint of adjusting the viscosity of the coating liquid to a preferred range, the amount of the monofunctional (meth) acrylate monomer used is preferably 10 parts by mass or more, and more preferably 10 to 80 parts by mass, based on 100 parts by mass of the total amount of the polymerizable compounds contained in the coating liquid.

-2-functional compounds- -

Examples of the polymerizable monomer having 2 polymerizable groups include 2-functional polymerizable unsaturated monomers having 2 groups containing an ethylenically unsaturated bond. The 2-functional polymerizable unsaturated monomer is suitable for making the composition low in viscosity. In the present embodiment, a (meth) acrylate compound having excellent reactivity and no problem such as residual catalyst is preferable.

In particular, neopentyl glycol di (meth) acrylate, 1, 9-nonanediol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, hydroxypivalic acid neopentyl glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, dicyclopentanyl di (meth) acrylate, and the like are preferably used in the present invention.

From the viewpoint of adjusting the viscosity of the coating liquid to a preferred range, the amount of the 2-functional (meth) acrylate monomer used is preferably 5 parts by mass or more, and more preferably 10 to 80 parts by mass, based on 100 parts by mass of the total amount of the polymerizable compounds contained in the coating liquid.

-3 or more functional compounds- -

Examples of the polymerizable monomer having 3 or more polymerizable groups include a polyfunctional polymerizable unsaturated monomer having 3 or more ethylenically unsaturated bond-containing groups. These polyfunctional polymerizable unsaturated monomers are preferable from the viewpoint of imparting mechanical strength. In the present embodiment, a (meth) acrylate compound having excellent reactivity and no problem such as residual catalyst is preferable.

Specifically, ech (ethylene oxide) modified glycerol tri (meth) acrylate, EO (ethylene oxide) modified glycerol tri (meth) acrylate, PO (propylene oxide) modified glycerol tri (meth) acrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, EO modified phosphate triacrylate, trimethylolpropane tri (meth) acrylate, caprolactone modified trimethylolpropane tri (meth) acrylate, EO modified trimethylolpropane tri (meth) acrylate, PO modified trimethylolpropane tri (meth) acrylate, tris (acryloyloxyethyl) isocyanurate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, caprolactone modified dipentaerythritol hexa (meth) acrylate, dipentaerythritol hydroxypenta (meth) acrylate, Alkyl-modified dipentaerythritol penta (meth) acrylate, dipentaerythritol poly (meth) acrylate, alkyl-modified dipentaerythritol tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol ethoxytetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, and the like.

Among these, EO-modified glycerol tri (meth) acrylate, PO-modified glycerol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, EO-modified trimethylolpropane tri (meth) acrylate, PO-modified trimethylolpropane tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, pentaerythritol ethoxytetra (meth) acrylate, pentaerythritol tetra (meth) acrylate are particularly preferable for the present invention.

The amount of the polyfunctional (meth) acrylate monomer used is preferably 5 parts by mass or more in terms of the strength of the coating film of the wavelength conversion layer after curing, and preferably 95 parts by mass or less in terms of suppressing gelation of the coating liquid, with respect to 100 parts by mass of the total amount of the polymerizable compound contained in the coating liquid.

In addition, the (meth) acrylate monomer is preferably an alicyclic acrylate from the viewpoint of further improving the heat resistance of the fluorescent region (adhesive). Examples of such monofunctional (meth) acrylate monomers include dicyclopentenyl (meth) acrylate, dicyclopentanyl (meth) acrylate, and dicyclopentenyloxyethyl (meth) acrylate. Examples of the 2-functional (meth) acrylate monomer include tricyclodecane dimethanol di (meth) acrylate.

From the viewpoint of handling and curability of the composition, the total amount of the polymerizable compounds in the curable composition forming the adhesive is preferably 70 to 99 parts by mass, and more preferably 85 to 97 parts by mass, based on 100 parts by mass of the curable composition.

Epoxy compounds and the like

Examples of the polymerizable monomer include compounds having a cyclic group such as a ring-opening polymerizable cyclic ether group such as an epoxy group or an oxetane group. As such a compound, a compound having an epoxy group (epoxy compound) can be more preferably exemplified. When a compound having an epoxy group or an oxetanyl group is used in combination with a (meth) acrylate compound, adhesion to a base film tends to be improved.

Examples of the compound having an epoxy group include polyglycidyl esters of polybasic acids, polyglycidyl ethers of polyhydric alcohols, polyglycidyl ethers of polyoxyalkylene glycols, polyglycidyl ethers of aromatic polyhydric alcohols, hydrogenated compounds of polyglycidyl ethers of aromatic polyhydric alcohols, urethane polyepoxy compounds, epoxidized polybutadienes, and the like. These compounds can be used alone or in combination of two or more.

Examples of the other compounds having an epoxy group which can be preferably used include aliphatic cyclic epoxy compounds, bisphenol a diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, brominated bisphenol a diglycidyl ether, brominated bisphenol F diglycidyl ether, brominated bisphenol S diglycidyl ether, hydrogenated bisphenol a diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, hydrogenated bisphenol S diglycidyl ether, 1, 4-butanediol diglycidyl ether, 1, 6-hexanediol diglycidyl ether, glycerol triglycidyl ether, trimethylolpropane triglycidyl ether, polyethylene glycol diglycidyl ether, and polypropylene glycol diglycidyl ether; polyglycidyl ethers of polyether polyols obtained by adding one or more alkylene oxides to aliphatic polyhydric alcohols such as ethylene glycol, propylene glycol, and glycerin; diglycidyl esters of aliphatic long-chain dibasic acids; monoglycidyl ethers of aliphatic higher alcohols; monoglycidyl ethers of phenols, cresols, butylphenols or polyether alcohols obtained by adding alkylene oxides to these; glycidyl esters of higher fatty acids, and the like.

Among these components, aliphatic cyclic epoxy compounds, bisphenol a diglycidyl ether, bisphenol F diglycidyl ether, hydrogenated bisphenol a diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, 1, 4-butanediol diglycidyl ether, 1, 6-hexanediol diglycidyl ether, glycerol triglycidyl ether, trimethylolpropane triglycidyl ether, neopentyl glycol diglycidyl ether, polyethylene glycol diglycidyl ether, and polypropylene glycol diglycidyl ether are preferable.

Commercially available products which can be preferably used as compounds having an Epoxy group or an oxetanyl group include UVR-6216 (manufactured by Union Carbide Corporation), Glycidol, AOEX24, CYCLOMER A200, CELLOXIDE 2021P, CELLOXIDE 8000 (manufactured by Daicel Chemical Industries, Ltd., above), 4-vinyl-1-cyclohexene diepoxide manufactured by Sigma-Aldrich Co.LLC, EPIKOTE 828, IKEPOTE 812, EPIKOTE 1031, EPIKOTE 872, EPIKOTE CT508 (manufactured by Yuka Shell Epoxy Co., Ltd., L., above), KRM-2400, KRM-2410, KRM-2408, KRM-2490, KRM-2720, KRM-2750 (manufactured by Asahi Denka Kogyo Co., Ltd., above), and the like. These can be used alone or in combination of two or more.

Further, The preparation method OF these compounds having An epoxy group or An oxetanyl group is not limited, and The compounds can be synthesized, for example, by reference to The documents OF Wan Kk Publication, The fourth edition OF Experimental chemistry lecture 20 organic Synthesis II, 213, Pincheng 4 years, ed. by Alfred Hasfner, The chemistry OF cosmetics composites-Small Ring Heterocycles part3Oxiranes, John & Wiley and Sons, An Interscience Publication, New York,1985, Jicun, Next 29 volumes 12, 32, 1985, and then 30 volumes 5, 42, 1986, and then 30 volumes 7, 42, 1986, Japanese patent laid-open No. 11-100378, Japanese patent No. 2906245, and Japanese patent No. 2926262.

As the polymerizable compound, a vinyl ether compound can be used.

The vinyl ether compound can be appropriately selected from known vinyl ether compounds, and for example, the vinyl ether compound described in paragraph 0057 of jp 2009-073078 a can be preferably used.

These vinyl ether compounds can be synthesized by, for example, the method described in stephen. c. lapin, Polymers Paint color journal.179(4237), 321(1988), that is, the reaction of a polyol or a polyhydric phenol with acetylene, or the reaction of a polyol or a polyhydric phenol with a halogenated alkyl vinyl ether, and these vinyl ether compounds can be used singly or in combination of two or more.

From the viewpoint of reducing the viscosity and increasing the hardness, the reactive group-containing silsesquioxane compound described in jp 2009-073078 a can be used in the coating liquid.

As the polymerizable compound contained in the curable composition for forming a fluorescent region binder, a (meth) acrylate compound, an epoxy compound, and the like are particularly preferable.

Among the polymerizable compounds, a (meth) acrylate compound is preferable, and an acrylate is more preferable, from the viewpoint of viscosity and photocurability of the composition. In the present invention, a polyfunctional polymerizable compound having 2 or more polymerizable functional groups is preferable. In the present invention, the blending ratio of the monofunctional (meth) acrylate compound to the polyfunctional (meth) acrylate compound is, in particular, preferably 80/20 to 0/100, more preferably 70/30 to 0/100, and still more preferably 40/60 to 0/100 in terms of weight ratio. By selecting an appropriate ratio, the composition can have sufficient curability and can have a low viscosity.

In the polyfunctional (meth) acrylate compound, the ratio of the 2-functional (meth) acrylate to the 3-or more-functional (meth) acrylate is preferably 100/0 to 20/80, more preferably 100/0 to 50/50, and still more preferably 100/0 to 70/30 in terms of a mass ratio. Since the viscosity of the 3-or more-functional (meth) acrylate is higher than that of the 2-functional (meth) acrylate, when the 2-functional (meth) acrylate is present in a large amount, the viscosity of the curable composition for forming the binder of the fluorescent region in the present invention can be reduced, which is preferable.

The polymerizable compound preferably further contains a substituent-containing compound having an aromatic structure and/or an alicyclic hydrocarbon structure, more preferably contains 50 mass% or more, and still more preferably contains 80 mass% or more of the polymerizable compound having an aromatic structure and/or an alicyclic hydrocarbon structure in the component. The polymerizable compound having an aromatic structure is preferably a (meth) acrylate compound having an aromatic structure. As the (meth) acrylate compound having an aromatic structure, a monofunctional (meth) acrylate compound having a naphthalene structure is particularly preferable, and examples thereof include 1-or 2-naphthyl (meth) acrylate, 1-or 2-naphthylmethyl (meth) acrylate, 1-or 2-naphthylethyl (meth) acrylate, monofunctional acrylates such as benzyl acrylate having a substituent on the aromatic ring, and 2-functional acrylates such as catechol (catechol) diacrylate and xylylene glycol diacrylate. As the polymerizable compound having an alicyclic hydrocarbon structure, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate, dicyclopentenyl (meth) acrylate, adamantyl (meth) acrylate, tricyclodecanyl (meth) acrylate, tetracyclododecyl (meth) acrylate, and the like are preferable.

When a (meth) acrylate is used as the polymerizable compound, an acrylate is more preferable than a methacrylate in terms of excellent curability.

< thixotropic agent >

The curable composition may contain a thixotropic agent.

The thixotropic agent is an inorganic compound or an organic compound.

Inorganic compounds-

The thixotropic agent is preferably a thixotropic agent of an inorganic compound in 1 mode, and for example, a needle-like compound, a chain compound, a flat compound, or a layered compound can be preferably used. Among them, a layered compound is preferable.

The layered compound is not particularly limited, and examples thereof include talc, mica, feldspar, kaolinite (kaolinite clay), pyrophyllite (pyrophyllite clay), sericite (sericite), bentonite, smectite and vermiculite (montmorillonite, beidellite, nontronite, saponite, etc.), organobentonite, and organosmectite.

They can be used alone or in combination of two or more. Examples of commercially available layered compounds include Crown Clay, Bages Clay #60, Bages Clay KF, Optiwhite (manufactured by SHIRAISHI KOGYO KAISHA, LTD.), Kaolin JP-100, NN Kaolin Glay, ST Kaolin Clay, Hardsil (manufactured by TSUCHIYAKOGYO CO., LTD.), ASP-072, Satenton Plus, TRANSLINK, Highdrascandamide NCD (manufactured by Enjer Hard Ltd.), Kaolin, OS Glay, HA Glay, HarMC d Glay (manufactured by MARUO CIUM CO., LTD. manufactured by Masentite SWN, Rusentite SAN, Rusentite STN, Rusentite SEN, Runstite SEN (manufactured by Co-CIUM CO., LTD. manufactured by RTD.), Hongtite SWN, Rusentite SAN, Rusentite STN, Rusentite SEN (manufactured by Co. CO., LTD. manufactured by Tankite, Bekuntson, Bekuntco, Bekunte.35, Bekuntson, Bekuntzie.g. No. 35, Bekuntb, Bekuntzier, Beproximate No. Bearind, Bekuntzier, Beproximate No. 35, Bekuntzier, Bedge, Bekuntb, Bedge., Laponite, Laponite RD, Laponite RDs (manufactured by Nippon silicon Kogyo Co ltd., supra), and the like. These compounds may be dispersed in a solvent.

Among the layered inorganic compounds, the thixotropic agent added to the coating liquid is preferably xM (I)₂O·ySiO₂Silicate compound (M (II) O, M (III) having oxidation numbers of 2 and 3)₂O₃An equivalent compound. x and y each represents a positive number), and is more preferableThe selected compounds are swelling layered clay minerals such as hectorite, bentonite, smectite, vermiculite, etc.

In particular, a layered (clay) compound modified with an organic cation (a compound obtained by exchanging an interlayer cation such as sodium of a silicate compound with an organic cation compound) can be suitably used, and for example, a compound obtained by exchanging a sodium ion of sodium magnesium silicate (hectorite) with the following ammonium ion can be mentioned.

Examples of the ammonium ion include monoalkyltrimethylammonium ions having an alkyl chain of 6 to 18 carbon atoms, dialkyldimethylammonium ions, trialkylmethylammonium ions, polyoxyethylene coconut oil alkylmethylammonium ions having an oxyethylene chain of 4 to 18, bis (2-hydroxyethyl) coconut oil alkylmethylammonium ions, polyoxypropylene methyldiethylammonium ions having an oxypropylene chain of 4 to 25, and the like. These ammonium ions can be used alone or in combination of two or more.

As a method for producing a silicate mineral modified with an organic cation, in which sodium ions of sodium magnesium silicate are exchanged with ammonium ions, sodium magnesium silicate is dispersed in water and sufficiently stirred, and then left to stand for 16 hours or more to prepare a 4 mass% dispersion. While stirring the dispersion, 30 to 200 mass% of a desired ammonium salt is added to the sodium magnesium silicate. After the addition, cation exchange occurs, and hectorite containing an ammonium salt between layers becomes insoluble in water and precipitates, and therefore the precipitate is filtered and dried to obtain a silicate mineral modified with an organic cation. In the preparation, heating may be performed in order to accelerate dispersion.

Commercially available products of alkylammonium-modified silicate minerals include Rusentite SAN, Rusentite SAN-316, Rusentite STN, Rusentite SEN, and Rusentite SPN (Co-op Chemical Co., Ltd.), and two or more thereof may be used alone or in combination.

In the present embodiment, as the thixotropic agent of the inorganic compound, silica, alumina, silicon nitride, titanium dioxide, calcium carbonate, zinc oxide, or the like can be used. These compounds can also be used to modify the hydrophilicity or hydrophobicity of the surface as desired.

Organic compounds-

Thixotropic agent a thixotropic agent of an organic compound can be used.

Examples of the thixotropic agent of the organic compound include oxidized polyolefin and modified urea.

The oxidized polyolefin may be prepared at home or may be a commercially available product. Examples of commercially available products include DISPARLON 4200-20 (trade name, manufactured by Kusumoto Chemicals, Ltd.), FLOWNON SA300 (trade name, manufactured by Kyoeisha Chemical Co., Ltd.).

The modified urea is a reactant of an isocyanate monomer or an adduct thereof and an organic amine. The modified urea may be prepared at home or may be a commercially available product. Examples of commercially available products include BYK410 (manufactured by BYK Additives & Instruments).

Content-

The content of the thixotropic agent in the coating liquid is preferably 0.15 to 20 parts by mass, more preferably 0.2 to 10 parts by mass, and particularly preferably 0.2 to 8 parts by mass, based on 100 parts by mass of the curable compound. In particular, in the case of a thixotropic agent of an inorganic compound, when the amount is 20 parts by mass or less based on 100 parts by mass of the curable compound, brittleness tends to be good.

< polymerization initiator >

The coating liquid may contain a known polymerization initiator as a polymerization initiator. As the polymerization initiator, for example, refer to paragraph 0037 of Japanese patent laid-open publication No. 2013-043382. The polymerization initiator is preferably 0.1 mol% or more, more preferably 0.5 to 2 mol% of the total amount of the polymerizable compounds contained in the coating liquid. The total curable composition excluding the volatile organic solvent preferably contains 0.1 to 10% by mass, more preferably 0.2 to 8% by mass.

Photopolymerization initiators

The curable composition preferably contains a photopolymerization initiator. As the photopolymerization initiator, any initiator can be used as long as it is a compound that generates an active species to polymerize the polymerizable compound by light irradiation. Examples of the photopolymerization initiator include a cationic polymerization initiator and a radical polymerization initiator, and a radical polymerization initiator is preferable. In the present invention, a plurality of photopolymerization initiators may be used simultaneously.

The content of the photopolymerization initiator is, for example, 0.01 to 15% by mass, preferably 0.1 to 12% by mass, and more preferably 0.2 to 7% by mass in all the compositions except the solvent. When two or more photopolymerization initiators are used, the total amount thereof falls within the above range.

When the content of the photopolymerization initiator is 0.01% by mass or more, the sensitivity (quick curability) and the strength of the coating film tend to be improved, and therefore, it is preferable. On the other hand, it is preferable to set the content of the photopolymerization initiator to 15% by mass or less because the light transmittance, the coloring property, the handling property, and the like tend to be improved. In a system containing a dye and/or a pigment, they may act as radical scavengers and affect the photopolymerization and sensitivity. In view of this, the amount of the photopolymerization initiator added is optimized in these applications. On the other hand, in the composition used in the present invention, the dye and/or the pigment are not essential components, and the optimum range of the photopolymerization initiator may be different from the optimum range in the field of curable compositions for color filters of liquid crystal displays and the like.

As the radical photopolymerization initiator, for example, a commercially available initiator can be used. As examples thereof, the initiators described in, for example, paragraph No. 0091 of Japanese patent application laid-open No. 2008-105414 can be preferably used. Among them, acetophenone compounds, acylphosphine oxide compounds, and oxime ester compounds are preferable from the viewpoint of curing sensitivity and absorption characteristics.

Preferable examples of the acetophenone compounds include hydroxyacetone compounds, dialkoxybenzophenone compounds, and aminobenzophenone compounds. Preferred examples of the hydroxyphenyl ketone compound include Irgacure (registered trademark) 2959(1- [4- (2-hydroxyethoxy) phenyl ] -2-hydroxy-2-methyl-1-propan-1-one), Irgacure (registered trademark) 184 (1-hydroxycyclohexyl phenyl ketone), Irgacure (registered trademark) 500 (1-hydroxycyclohexyl phenyl ketone, benzophenone), Darocur (registered trademark) 1173 (2-hydroxy-2-methyl-1-phenyl-1-propan-1-one) available from BASF corporation. As the dialkoxybenzophenone compound, Irgacure (registered trademark) 651(2, 2-dimethoxy-1, 2-diphenylethan-1-one) available from BASF corporation is preferably mentioned.

Preferable examples of the aminoacetophenone compound include Irgacure (registered trademark) 369 (2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1), Irgacure (registered trademark) 379(EG) (2-dimethylamino-2- (4-methylbenzyl) -1- (4-morpholin-4-ylphenyl) butan-1-one), and Irgacure (registered trademark) 907 (2-methyl-1 [ 4-methylthiophenyl ] -2-morpholinopropan-1-one), which are available from BASF corporation.

As the acylphosphine oxide compound, Irgacure (registered trademark) 819 (bis (2,4, 6-trimethylbenzoyl) -phenylphosphine oxide) available from BASF, Irgacure (registered trademark) 1800 (bis (2, 6-dimethoxybenzoyl) -2,4, 4-trimethyl-pentylphosphine oxide), Lucirin TPO (2,4, 6-trimethylbenzoyldiphenylphosphine oxide) available from BASF, Lucirin TPO-L (2,4, 6-trimethylbenzoylphenylethoxyphosphine oxide) may be preferably mentioned.

Examples of the oxime ester compounds include Irgacure (registered trademark) OXE01(1, 2-octanedione, 1- [4- (phenylthio) phenyl ] -2- (O-benzoyl oxime), Irgacure (registered trademark) OXE02 (ethanone, 1- [ 9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl ] -,1- (O-acetyl oxime), which are available from BASF corporation.

As the cationic photopolymerization initiator, sulfonium salt compounds, iodonium salt compounds, oxime sulfonate compounds and the like are preferable, and examples thereof include 4-methylphenyl [4- (1-methylethyl) phenyliodonium tetrakis (pentafluorophenyl) borate (PI 2074 manufactured by Rhodia), 4-methylphenyl [4- (2-methylpropyl) phenyliodonium hexafluorophosphate (IRGACURE 250 manufactured by BASF), IRGACURE PAG103, 108, 121, 203 (manufactured by BASF) and the like.

The photopolymerization initiator needs to be appropriately selected for the wavelength of the light source used, and is preferably one that does not generate gas during mold pressurization/exposure. If gas is generated, the mold is contaminated, and therefore, the mold has to be frequently cleaned, or the photocurable composition is deformed in the mold, which causes problems such as deterioration of the accuracy of the transferred pattern.

The curable composition for forming the binder of the fluorescent region 35 is preferably a radical polymerizable curable composition in which the polymerizable compound is a radical polymerizable compound and the photopolymerization initiator is a radical polymerization initiator that generates radicals by light irradiation.

(Polymer)

The curable composition forming the adhesive may contain a polymer. Examples of the polymer include poly (meth) acrylate, poly (meth) acrylamide, polyester, polyurethane, polyurea, polyamide, polyether, and polystyrene.

(Polymer dispersant)

The curable composition forming the binder may include a polymeric dispersant for dispersing the quantum dots in the binder.

The polymer dispersant is a compound having a coordinating group coordinated to the surface of the quantum dot and represented by the following general formula I.

The polymer dispersant having the structure of the general formula I is hardly desorbed because it is adsorbed in multiple points, and can impart high dispersibility. Further, since the adsorbing groups are densely located at the ends, it is difficult to crosslink between particles, and an increase in liquid viscosity which causes entrainment of bubbles can be suppressed.

[ chemical formula 1]

In the general formula I, A is an organic group having a coordinating group coordinated to the quantum dot, Z is an (n + m + l) -valent organic linking group, and X¹And X²Is a single bond or a 2-valent organic linking group, R¹Represents an alkyl group, an alkenyl group or an alkynyl group which may have a substituent, and P is a group having a structure containing a group selected from a polyacrylate skeleton having a polymerization degree of 3 or more, a polymethacrylate skeleton, and polypropyleneA polymer chain group of at least 1 polymer skeleton selected from an amide skeleton, a polymethacrylamide skeleton, a polyester skeleton, a polyurethane skeleton, a polyurea skeleton, a polyamide skeleton, a polyether skeleton, a polyvinyl ether skeleton, and a polystyrene skeleton. n and m are each independently a number of 1 or more, l is a number of 0 or more, and n + m + l is an integer of 2 or more and 10 or less. The n A's may be the same or different. The m P's may be the same or different. l X¹And R¹Each may be the same or different.

In the general formula I, X¹And X²Represents a single bond or a 2-valent organic linking group. The organic linking group having a valence of 2 includes a group consisting of 1 to 100 carbon atoms, 0 to 10 nitrogen atoms, 0 to 50 oxygen atoms, 1 to 200 hydrogen atoms and 0 to 20 sulfur atoms, and may be unsubstituted or substituted.

Organic linking group X of valency 2¹And X²Preference is given to single bonds or 2-valent organic connecting groups composed of 1 to 50 carbon atoms, 0 to 8 nitrogen atoms, 0 to 25 oxygen atoms, 1 to 100 hydrogen atoms and 0 to 10 sulfur atoms. More preferably a single bond or a 2-valent organic linking group consisting of 1 to 30 carbon atoms, 0 to 6 nitrogen atoms, 0 to 15 oxygen atoms, 1 to 50 hydrogen atoms and 0 to 7 sulfur atoms. Particularly preferred are single bonds or 2-valent organic linking groups composed of 1 to 10 carbon atoms, 0 to 5 nitrogen atoms, 0 to 10 oxygen atoms, 1 to 30 hydrogen atoms and 0 to 5 sulfur atoms.

With respect to the 2-valent organic linking group X¹And X²Specific examples thereof include groups (which may form a ring structure) composed of a combination of the following structural units.

[ chemical formula 2]

When the organic linking group X is 2 valent ¹And X²When having a substituent, examples of the substituent include a carbon atom such as methyl group and ethyl groupAn aryl group having 6 to 16 carbon atoms such as an alkyl group having 1 to 20 carbon atoms, a phenyl group, a naphthyl group, a hydroxy group, an amino group, a carboxy group, a sulfonamide group, an N-sulfonamide group, an acyloxy group having 1 to 6 carbon atoms such as an acetoxy group, an alkoxy group having 1 to 6 carbon atoms such as a methoxy group, an ethoxy group, a halogen atom such as a chlorine or bromine atom, a methoxycarbonyl group, an ethoxycarbonyl group, a cyclohexyloxycarbonyl group, an alkoxycarbonyl group having 2 to 7 carbon atoms such as a methoxycarbonyl group, a cyano group, a carbonate group such as a tert-butyl carbonate group, and the like.

The (n + m + l) -valent organic linking group represented by Z includes a group consisting of 1 to 100 carbon atoms, 0 to 10 nitrogen atoms, 0 to 50 oxygen atoms, 1 to 200 hydrogen atoms, and 0 to 20 sulfur atoms, and may be unsubstituted or may further have a substituent.

As the (n + m + l) -valent organic linking group Z, a group composed of 1 to 60 carbon atoms, 0 to 10 nitrogen atoms, 0 to 40 oxygen atoms, 1 to 120 hydrogen atoms, and 0 to 10 sulfur atoms is preferable, a group composed of 1 to 50 carbon atoms, 0 to 10 nitrogen atoms, 0 to 30 oxygen atoms, 1 to 100 hydrogen atoms, and 0 to 7 sulfur atoms is more preferable, and a group composed of 1 to 40 carbon atoms, 0 to 8 nitrogen atoms, 0 to 20 oxygen atoms, 1 to 80 hydrogen atoms, and 0 to 5 sulfur atoms is particularly preferable.

The (n + m + l) -valent organic linking group Z includes the following structural units or groups composed of a combination of structural units (a ring structure may be formed).

[ chemical formula 3]

Specific examples (1) to (20) of the (n + m + l) -valent organic linking group Z are shown below. However, the present invention is not limited to these. (ii) the organic linking group is represented by A, X in the general formula I¹And X²The site of bonding.

[ chemical formula 4]

[ chemical formula 5]

[ chemical formula 6]

When the (N + m + l) -valent organic linking group Z has a substituent, examples of the substituent include an alkyl group having 1 to 20 carbon atoms such as a methyl group or an ethyl group, an aryl group having 6 to 16 carbon atoms such as a phenyl group or a naphthyl group, a hydroxyl group, an amino group, a carboxyl group, a sulfonamide group, an N-sulfonylamido group, an acyloxy group having 1 to 6 carbon atoms such as an acetoxy group, an alkoxy group having 1 to 6 carbon atoms such as a methoxy group or an ethoxy group, a halogen atom such as a chlorine or bromine atom, an alkoxycarbonyl group having 2 to 7 carbon atoms such as a methoxycarbonyl group, an ethoxycarbonyl group or a cyclohexyloxycarbonyl group, a cyano group, a carbonate group such as a tert-butyl carbonate group, and the like.

Among the above-mentioned specific examples, the most preferable (n + m + l) -valent organic linking group Z is the following group from the viewpoints of availability of raw materials, easy synthesis, and solubility in monomers and various solvents.

[ chemical formula 7]

In the general formula I, R¹Is an alkyl group, an alkenyl group or an alkynyl group which may have a substituent. The number of carbon atoms is preferably 1 to 30, and more preferably 1 to 20. Examples of the substituent include an alkyl group having 1 to 20 carbon atoms such as a methyl group or an ethyl group, an aryl group having 6 to 16 carbon atoms such as a phenyl group or a naphthyl group, a hydroxyl group, an amino group, a carboxyl group, a sulfonamide group, an N-sulfonylamido group, an acyloxy group having 1 to 6 carbon atoms such as an acetoxy group, an alkoxy group having 1 to 6 carbon atoms such as a methoxy group or an ethoxy group, a chlorine groupHalogen atoms such as bromine, and carbonate groups such as alkoxycarbonyl groups having 2 to 7 carbon atoms such as methoxycarbonyl group, ethoxycarbonyl group and cyclohexyloxycarbonyl group, cyano groups and tert-butyl carbonate.

The polymer chain P in the present invention is a chain containing at least 1 polymer skeleton selected from a polyacrylate skeleton, a polymethacrylate skeleton, a polyacrylamide skeleton, a polymethacrylamide skeleton, a polyester skeleton, a polyurethane skeleton, a polyurea skeleton, a polyamide skeleton, a polyether skeleton, a polyvinyl ether skeleton, and a polystyrene skeleton having a polymerization degree of 3 or more, and also includes a polymer, a modified product, or a copolymer having these polymer skeletons. For example, polyether/polyurethane copolymers, polyether/vinyl monomer copolymers, and the like can be cited. The polymer chain may be any of a random copolymer, a block copolymer, and a graft copolymer. Among them, a polymer or copolymer comprising a polyacrylate skeleton is particularly preferable.

Further, the polymer chain is preferably soluble in a solvent. If the affinity with the solvent is low, for example, when the ligand is used, the affinity with the dispersion medium is reduced, and an adsorption layer sufficient for stabilizing the dispersion may not be secured.

The monomer forming the polymer chain P is not particularly limited, and examples thereof include (meth) acrylates, crotonates, vinyl esters, maleic acid diesters, fumaric acid diesters, itaconic acid diesters, aliphatic polyesters, (meth) acrylamides, aliphatic polyamide styrenes, vinyl ethers, vinyl ketones, olefins, maleimides, (meth) acrylonitrile, and monomers having an acidic group.

Preferred examples of these monomers are described below.

Examples of the (meth) acrylic esters include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, t-octyl (meth) acrylate, dodecyl (meth) acrylate, octadecyl (meth) acrylate, acetoxyethyl (meth) acrylate, phenyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, dodecyl (meth) acrylate, octadecyl (meth) acrylate, and the like, 4-hydroxybutyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2- (2-methoxyethoxy) ethyl (meth) acrylate, 3-phenoxy-2-hydroxypropyl (meth) acrylate, 2-chloroethyl (meth) acrylate, glycidyl (meth) acrylate, 3, 4-epoxycyclohexylmethyl (meth) acrylate, vinyl (meth) acrylate, 2-phenylethyl (meth) acrylate, 1-propenyl (meth) acrylate, allyl (meth) acrylate, 2-allyloxyethyl (meth) acrylate, propargyl (meth) acrylate, benzyl (meth) acrylate, diethylene glycol monomethyl ether (meth) acrylate, and the like, Diethylene glycol monoethyl ether (meth) acrylate, triethylene glycol monomethyl ether (meth) acrylate, triethylene glycol monoethyl ether (meth) acrylate, polyethylene glycol monomethyl ether (meth) acrylate, polyethylene glycol monoethyl ether (meth) acrylate, beta-phenoxyethoxyethyl (meth) acrylate, nonylphenoxypolyethylene glycol (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, trifluoroethyl (meth) acrylate, octafluoropentyl (meth) acrylate, perfluorooctylethyl (meth) acrylate, dicyclopentanyl (meth) acrylate, tribromophenyl (meth) acrylate, tribromophenoxyethyl (meth) acrylate, γ -butyrolactone (meth) acrylate, and the like.

Examples of the crotonic acid esters include butyl crotonate and hexyl crotonate.

Examples of the vinyl esters include vinyl acetate, vinyl chloroacetate, vinyl propionate, vinyl butyrate, vinyl methoxyacetate, and vinyl benzoate.

Examples of the diesters of maleic acid include dimethyl maleate, diethyl maleate, dibutyl maleate, and the like.

Examples of the fumaric acid diesters include dimethyl fumarate, diethyl fumarate, and dibutyl fumarate.

Examples of the itaconate diester include dimethyl itaconate, diethyl itaconate, dibutyl itaconate, and the like.

Examples of the aliphatic polyester group include polycaprolactone and polypentanolactone.

Examples of the (meth) acrylamide include (meth) acrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-propyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N-N-butyl (meth) acrylamide, N-tert-butyl (meth) acrylamide, N-cyclohexyl (meth) acrylamide, N- (2-methoxyethyl) (meth) acrylamide, N-dimethyl (meth) acrylamide, N-diethyl (meth) acrylamide, N-phenyl (meth) acrylamide, N-nitrophenylacrylamide, N-ethyl-N-phenylacrylamide, N-benzyl (meth) acrylamide, N-butyl (meth) acrylamide, N-cyclohexyl (meth) acrylamide, N-2-methyl (meth) acrylamide, N-benzyl (meth) acrylamide, N, (meth) acryloylmorpholine, diacetone acrylamide, N-methylolacrylamide, N-hydroxyethylacrylamide, vinyl (meth) acrylamide, N-diallyl (meth) acrylamide, N-allyl (meth) acrylamide and the like.

Examples of the aliphatic polyamides include polycaprolactam and polypentanolactam.

Examples of the styrenes include styrene, methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, isopropylstyrene, butylstyrene, hydroxystyrene, methoxystyrene, butoxystyrene, acetoxystyrene, chlorostyrene, dichlorostyrene, bromostyrene, chloromethylstyrene, hydroxystyrene protected with a group deprotectable by an acidic substance (e.g., t-Boc), methyl vinylbenzoate, and α -methylstyrene.

Examples of the vinyl ether include methyl vinyl ether, ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, hexyl vinyl ether, octyl vinyl ether, methoxyethyl vinyl ether, and phenyl vinyl ether.

Examples of the vinyl ketone include methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, and phenyl vinyl ketone.

Examples of the olefins include ethylene, propylene, isobutylene, butadiene, isoprene, and the like.

Examples of the maleimide include maleimide, butylmaleimide, cyclohexylmaleimide, and phenylmaleimide.

It is also possible to use (meth) acrylonitrile, vinyl-substituted heterocyclic groups (e.g., vinylpyridine, N-vinylpyrrolidone, vinylcarbazole, etc.), N-vinylformamide, N-vinylacetamide, N-vinylimidazole, vinylcaprolactone, etc.

The polymer chain P is more preferably a group represented by the following general formula P1.

[ chemical formula 8]

In the general formula P1, E is represented by-O-, -CO-, -COO-, -COOR^yA substituent consisting of at least 1 of epoxy group, oxetane group, alicyclic epoxy group, alkylene group, alkyl group and alkenyl group, R^yIs a hydrogen atom or an alkyl group of 1 to 6 carbon atoms, R²Is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. np is a number of 3 to 500. Plural E and R²Each may be the same or different.

Examples of the polymer chain represented by the general formula P1 include the following polymer chains.

np is preferably 3 to 500, more preferably 4 to 200, and further preferably 5 to 100.

[ chemical formula 9]

The polymer dispersant may be a compound represented by the following general formula II in which n, m and l are 1 and 0 in the general formula I.

[ chemical formula 10]

A is preferably a group represented by the following general formula A1.

[ chemical formula 11]

In the formula A1, X³Is a single bond or a 2-valent organic linking group, X⁴Is an (a1+1) -valent organic linking group, L is a coordinating group, and a1 is an integer of 1 to 2 inclusive. X³Has the meaning of (A) and X in the formula I²Similarly, the preferred ranges are also the same.

Organic linking groups X having a valency of (a1+1)⁴Preferably, a group composed of 1 to 60 carbon atoms, 0 to 10 nitrogen atoms, 0 to 40 oxygen atoms, 1 to 120 hydrogen atoms and 0 to 10 sulfur atoms, more preferably a group composed of 1 to 50 carbon atoms, 0 to 10 nitrogen atoms, 0 to 30 oxygen atoms, 1 to 100 hydrogen atoms and 0 to 7 sulfur atoms, and particularly preferably a group composed of 1 to 40 carbon atoms, 0 to 8 nitrogen atoms, 0 to 20 oxygen atoms, 1 to 80 hydrogen atoms and 0 to 5 sulfur atoms.

Organic linking groups X having a valency of (a1+1)⁴Specific examples of (a) include the following structural units or groups composed of a combination of structural units (a ring structure may be formed).

[ chemical formula 12]

Organic linking group X having valence of (a1+1)⁴When having a substituent, examples of the substituent include a carbon atom such as methyl group and ethyl group An aryl group having 6 to 16 carbon atoms such as an alkyl group having 1 to 20 carbon atoms, a phenyl group, a naphthyl group, a hydroxy group, an amino group, a carboxy group, a sulfonamide group, an N-sulfonylamido group, an acyloxy group having 1 to 6 carbon atoms such as an acetoxy group, an alkoxy group having 1 to 6 carbon atoms such as a methoxy group, an ethoxy group, a halogen atom such as a chlorine or bromine atom, a methoxycarbonyl group, an ethoxycarbonyl group, a cyclohexyloxycarbonyl group, an alkoxycarbonyl group having 2 to 7 carbon atoms such as a methoxycarbonyl group, a cyano group, a carbonate group such as a tert-butyl carbonate, and the like.

The coordinating group L is preferably at least 1 selected from the group consisting of an amino group, a carboxyl group, a mercapto group, a phosphino group and a phosphinoxide group. Among them, carboxyl group and phosphine oxide group are more preferable.

In the general formula A1, the organic linking group X containing a coordinating group L and a valence of 2⁴The following groups are preferred. In the following groups³The site of bonding.

[ chemical formula 13]

Such X⁴Has a length of less than about 1nm and has a plurality of coordinating groups within the length. Therefore, the ligand can be multi-point adsorbed on the quantum dot in a denser state, and thus is strongly coordinated. Thus, the ligand of the quantum dot is not detached and covers the surface of the quantum dot, and therefore, the generation of the surface level of the surface of the quantum dot, the oxidation of the quantum dot, and the aggregation of the quantum dot can be prevented, and the decrease in the light emission efficiency can be suppressed. Even when the ligand is already coordinated to the quantum dot, the polymer dispersant can enter the gap between the ligands, and the decrease in the light emission efficiency of the quantum dot can be suppressed.

The polymeric dispersant may be a compound represented by the following general formula III.

[ chemical formula 14]

In the general formula III，X⁵And X⁶Is a single bond or a 2-valent organic linking group, R³And R⁴Is an alkyl group having 1 to 6 hydrogen atoms or carbon atoms, and P is a group having a polymer chain containing at least 1 polymer skeleton selected from a polyacrylate skeleton, a polymethacrylate skeleton, a polyacrylamide skeleton, a polymethacrylamide skeleton, a polyester skeleton, a polyurethane skeleton, a polyurea skeleton, a polyamide skeleton, a polyether skeleton, a polyvinyl ether skeleton, and a polystyrene skeleton, the polymerization degree of which is 3 or more. a and b are each independently a number of 1 or more, and a + b is 2 or more and 1000 or less. Each of the plurality of ls may be the same or different. Each of the plurality of P may be the same or different.

X⁵And X⁶Is a single bond or a 2-valent organic linking group. X as a 2-valent organic linking group⁵And X⁶With the 2-valent organic linking group X in the formula I²The same is true. In particular, from the viewpoint of availability of materials or easy synthesis, groups containing-COO-, -CONH-, -O-, and the like are preferable.

R³And R⁴An alkyl group having 1 to 6 carbon atoms, preferably a hydrogen atom or a methyl group.

As the polymer chain P in the general formula III, the following polymer chain is preferable.

[ chemical formula 15]

In the polymer chain P, np is preferably 3 to 300, more preferably 4 to 200, and still more preferably 5 to 100.

Specific examples of the polymer dispersant represented by the general formula III include the following polymer dispersants.

[ chemical formula 16]

The ratio of a to b of the polymeric dispersant is preferably 1:9 to 7:3, more preferably 2:8 to 5: 5.

The molecular weight of the polymeric dispersant is preferably 2000 to 100000, more preferably 3000 to 50000, and particularly preferably 5000 to 30000 in terms of weight average molecular weight. When the weight average molecular weight is within this range, the quantum dots can be well dispersed in the propylene-based monomer.

(Synthesis of Polymer dispersant)

The ligands of the general formulae I and II can be synthesized by known synthesis methods. For example, in the method described in Japanese patent laid-open No. 2007-277514, the synthesis can be performed by replacing the organic dye site with a coordinating site.

The polymeric dispersants of the general formula III can be synthesized by copolymerization of the corresponding monomers or by a polymeric reaction with a precursor polymer. Examples of the monomer having a steric exclusion group in a side chain include commercially available products such as BLEMMER AE-400(NOF CORPORATION) and BLEMMER AP-800(NOF CORPORATION).

(other additives)

The coating liquid for forming a fluorescent region of the curable composition containing the phosphor 31 and the binder 33 may contain a viscosity adjuster, a silane coupling agent, a surfactant, an antioxidant, an oxygen getter (oxygen gel agent), a polymerization inhibitor, scattering particles, a refractive index adjuster, and the like.

Viscosity regulators-

The coating liquid for forming a fluorescent region may contain a viscosity modifier as necessary. By adding a viscosity modifier, they can be adjusted to a desired viscosity. The viscosity modifier is preferably a filler having a particle diameter of 5nm to 300 nm. The viscosity modifier may be a thixotropic agent. In addition, in the present invention and in the present specification, thixotropy means a property of decreasing viscosity in a liquid composition with respect to an increase in shear rate, and a thixotropic agent means a material having a function of imparting thixotropy to the composition by containing it in the liquid composition. Specific examples of the thixotropic agent include Fumed silica (fused silica), alumina, silicon nitride, titanium dioxide, calcium carbonate, zinc oxide, talc, mica, feldspar, kaolinite (kaolinite clay), pyrophyllite (pyrophyllite clay), sericite (serite), bentonite, smectite-vermiculite (montmorillonite, beidellite, nontronite, saponite, etc.), organic bentonite, organic smectite, and the like.

Surfactants-

The coating liquid for forming a fluorescent region may contain at least one surfactant containing 20 mass% or more of fluorine atoms.

Antioxidants-

The coating liquid for forming a fluorescent region preferably contains a known antioxidant. The antioxidant can inhibit discoloration caused by heat and light irradiation and ozone, active oxygen, and NO_x、SO_xDiscoloration of the substrate due to various oxidizing gases (X is an integer). In particular, the addition of an antioxidant in the present invention has an advantage that the coloring of the cured film can be prevented or the decrease in the film thickness due to decomposition can be reduced.

As the antioxidant, two or more antioxidants can be used.

In the curable compound, the antioxidant is preferably 0.2% by mass or more, more preferably 1% by mass or more, and further preferably 2% by mass or more, based on the total mass of the curable compound. On the other hand, the antioxidant may deteriorate due to interaction with oxygen. The antioxidant which is deteriorated may induce decomposition of each component in the coating liquid for forming a fluorescent region, thereby causing decrease in adhesiveness, deterioration in brittleness, and decrease in quantum dot light efficiency. From the viewpoint of preventing these problems, it is preferably 20% by mass or less, more preferably 15% by mass or less, and still more preferably 10% by mass or less.

As the antioxidant, at least one of a radical scavenger, a metal deactivator, a singlet oxygen scavenger, a peroxide scavenger, or a hydroxyl radical scavenger is preferable. Examples of such antioxidants include phenol antioxidants, hindered amine antioxidants, quinone antioxidants, phosphorus antioxidants, thiol antioxidants, and the like.

Examples of the phenolic antioxidant include 2, 6-di-t-butyl-p-cresol, 2, 6-diphenyl-4-octadecyloxyphenol, distearyl (3, 5-di-t-butyl-4-hydroxybenzyl) phosphonate, 1, 6-hexamethylenebis [ (3, 5-di-t-butyl-4-hydroxyphenyl) propionamide ], 4 ' -thiobis (6-t-butyl-m-cresol), 2 ' -methylenebis (4-methyl-6-t-butylphenol), 2 ' -methylenebis (4-ethyl-6-t-butylphenol), 4 ' -butylidenebis (6-t-butyl-m-cresol), 2 ' -ethylidenebis (4, 6-di-tert-butylphenol), 2' -ethylenebis (4-sec-butyl-6-tert-butylphenol), 1, 3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3, 5-tris (2, 6-dimethyl-3-hydroxy-4-tert-butylbenzyl) isocyanurate, 1,3, 5-tris (3, 5-di-tert-butyl-4-hydroxybenzyl) -2,4, 6-trimethylbenzene, 2-tert-butyl-4-methyl-6- (2-acryloyloxy-3-tert-butyl-5-methylbenzyl) phenol, Stearyl (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, methyl tetrakis [ 3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] methane (Adekastab AO-60 (manufactured by ADEKA CORPORATION)), thiodiethylene glycol bis [ (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], 1, 6-hexamethylenebis [ (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], bis [ 3, 3-bis (4-hydroxy-3-tert-butylphenyl) butyrate ] diol, bis [ 2-tert-butyl-4-methyl-6- (2-hydroxy-3-tert-butyl-5-methylbenzyl) phenyl ] terephthalate, and mixtures thereof, 1,3, 5-tris [ (3, 5-di-tert-butyl-4-hydroxyphenyl) propionyloxyethyl ] isocyanurate, 3, 9-bis [ 1, 1-dimethyl-2- { (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy } ethyl ] -2,4,8, 10-tetraoxaspiro [ 5,5 ] undecane, triethylene glycol bis [ (3-tert-butyl-4-hydroxy-5-methylphenyl) propionate ], and the like.

Examples of the phosphorus-based antioxidant include trisnonylphenyl phosphite, tris [ 2-tert-butyl-4- (3-tert-butyl-4-hydroxy-5-methylphenylsulfanyl) -5-methylphenyl ] phosphite, tridecyl phosphite, octyldiphenyl phosphite, didecyl monophenyl phosphite, ditridecyl pentaerythritol diphosphite, bis (nonylphenyl) pentaerythritol diphosphite, bis (2, 4-di-tert-butylphenyl) pentaerythritol diphosphite, bis (2, 6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, bis (2,4, 6-tri-tert-butylphenyl) pentaerythritol diphosphite, bis (2, 4-dicumylphenyl) pentaerythritol diphosphite, tris (2, 4-dicumylphenyl) pentaerythritol diphosphite, ditridecyl-4-methylphenyl) pentaerythritol diphosphite, and the like, Tetratridecyl isopropylidenediphenol diphosphite, tetrakis (tridecyl) -4,4 ' -n-butylidenebis (2-tert-butyl-5-methylphenol diphosphite), hexa (tridecyl) -1,1, 3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butanetriphosphite, tetrakis (2, 4-di-tert-butylphenyl) biphenylene diphosphonite, 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2 ' -methylenebis (4, 6-tert-butylphenyl) -2-ethylhexyl phosphite, 2 ' -methylenebis (4, 6-tert-butylphenyl) -octadecyl phosphite, octadecyl ester, tert-butylphenyl ester, 2, 2' -ethylenebis (4, 6-di-t-butylphenyl) fluorophosphite; phosphite esters of tris (2- [ (2,4,8, 10-tetra-tert-butyldibenzo [ d, f ] -1, 3,2 ] dioxaphosphepin-6-yl) oxy ] ethyl) amine, 2-ethyl-2-butylpropanediol and 2,4, 6-tri-tert-butylphenol, and the like. The amount of the phosphorus antioxidant added is preferably 0.001 to 10 parts by mass, and particularly preferably 0.05 to 5 parts by mass, based on 100 parts by mass of the polyolefin resin.

Examples of the thiol antioxidant include dialkyl thiodipropionate esters such as dilauryl thiodipropionate, dimyristyl thiodipropionate, and distearyl thiodipropionate; and pentaerythritol tetrakis (. beta. -alkylmercaptopropionic acid) esters.

Hindered amine antioxidants are also called HALS (Hindered amine light stabilizers) and have a structure in which all hydrogen atoms on carbons at positions 2 and 6 of piperidine are substituted with methyl groups, and are preferably groups represented by formula 1 below. Wherein, X in formula 1 represents a hydrogen atom or an alkyl group. Among the groups represented by the following formula 1, HALS having a 2,2,6, 6-tetramethyl-4-piperidyl group wherein X is a hydrogen atom or a 1,2,2,6, 6-pentamethyl-4-piperidyl group wherein X is a methyl group are particularly preferably used. Further, HALS having a structure in which a group represented by formula 1 is bonded to a-COO-group, that is, a group represented by formula 2 below, are commercially available in a large number, and these can be preferably used.

[ chemical formula 17]

Specifically, the HALS preferably used in the present invention includes, for example, HALS represented by the following formula. Wherein R represents a 2,2,6, 6-tetramethyl-4-piperidyl group, and R' represents a 1,2,2,6, 6-pentamethyl-4-piperidyl group.

ROC(＝O)(CH₂)₈C(＝O)OR、ROC(＝O)C(CH₃)＝CH₂、R’OC(＝O)C(CH₃)＝CH₂、CH₂(COOR)CH(COOR)CH(COOR)CH₂COOR、CH₂(COOR’)CH(COOR’)CH(COOR’)CH₂COOR' and a compound represented by the formula 3.

[ chemical formula 18]

Specific examples thereof include 2,2,6, 6-tetramethyl-4-piperidyl stearate, 1,2,2,6, 6-pentamethyl-4-piperidyl stearate, 2,2,6, 6-tetramethyl-4-piperidyl benzoate, bis (2,2,6, 6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6, 6-pentamethyl-4-piperidyl) sebacate, bis (1-octyloxy-2, 2,6, 6-tetramethyl-4-piperidyl) sebacate, tetrakis (2,2,6, 6-tetramethyl-4-piperidyl) -1,2,3, 4-butane tetracarboxylic acid ester, tetrakis (1,2,2,6, 6-pentamethyl-4-piperidyl) -1,2,3, 4-butanetetracarboxylate, bis (2,2,6, 6-tetramethyl-4-piperidyl)/ditridecyl) -1,2,3, 4-butanetetracarboxylate, bis (1,2,2,6, 6-pentamethyl-4-piperidyl)/ditridecyl) -1,2,3, 4-butanetetracarboxylate, bis (1,2,2,4, 4-pentamethyl-4-piperidyl) -2-butyl-2- (3, 5-di-tert-butyl-4-hydroxybenzyl) malonate, 1- (2-hydroxyethyl) -2,2,6, 6-tetramethyl-4-piperidinol/diethyl succinate polycondensate, 1, 6-bis (2,2,6, 6-tetramethyl-4-piperidylamino) hexane/2, 4-dichloro-6-morpholino-s-triazine polycondensate, 1, 6-bis (2,2,6, 6-tetramethyl-4-piperidylamino) hexane/2, 4-dichloro-6-trioctylamino-s-triazine polycondensate, 1,5,8, 12-tetrakis [ 2, 4-bis (N-butyl-N- (2,2,6, 6-tetramethyl-4-piperidylamino) -s-triazin-6-yl ] -1,5,8, 12-tetraazadodecane, 1,5,8, 12-tetrakis [ 2, 4-bis (N-butyl-N- (1, hindered amine compounds such as 2,2,6, 6-pentamethyl-4-piperidyl) amino) -s-triazin-6-yl ] -1,5,8, 12-tetraazadodecane, 1,6, 11-tris [ 2, 4-bis (N-butyl-N- (2,2,6, 6-tetramethyl-4-piperidyl) amino) -s-triazin-6-yl ] aminoundecane, and 1,6, 11-tris [ 2, 4-bis (N-butyl-N- (1,2,2,6, 6-pentamethyl-4-piperidyl) amino) -s-triazin-6-yl ] aminoundecane.

Specific examples of the commercial products include Tinuvin 123, Tinuvin 144, Tinuvin 765, Tinuvin 770, Tinuvin 622, Chimassorb 944, Chimassorb 119 (both trade names of Ciba Specialty Chemicals inc.), adekasab LA52, adekasab LA57, adekasab LA62, adekasab LA67, adekasab LA82, adekasab LA87, and adekasab LX335 (both trade names of Asahi Denka Kogyo co.

Among the HALS, HALS having relatively small molecules are preferable because they easily diffuse from the resin layer to the fluorescent region. From this viewpoint, ROC (═ O) (CH) is a preferred HALS₂)₈C(＝O)OR、R’OC(＝O)C(CH₃)＝CH₂The compounds represented by the formula (I), and the like.

Among the antioxidants, at least one of a hindered phenol compound, a hindered amine compound, a quinone compound, a hydroquinone compound, a tocopherol compound, an aspartic acid compound, or a thiol compound is more preferable, and at least one of a citric acid compound, an ascorbic acid compound, or a tocopherol compound is further preferable. These compounds are not particularly limited, and examples thereof include hindered phenols, hindered amines, quinones, hydroquinones, tocopherols, aspartic acid, thiols, citric acid, tocopheryl acetates and tocopheryl phosphates, and salts or ester compounds thereof.

An example of the antioxidant is shown below.

[ chemical formula 19]

[ chemical formula 20]

[ chemical formula 21]

[ chemical formula 22]

[ chemical formula 23]

[ chemical formula 24]

[ chemical formula 25]

[ chemical formula 26]

[ chemical formula 27]

Oxygen-absorbing agents

As the oxygen getter, a known substance used as a getter for an organic EL element or the like can be used, and any of an inorganic getter and an organic getter can be used, and at least one compound selected from a metal oxide, a metal halide, a metal sulfate, a metal perchlorate, a metal carbonate, a metal alkoxide, a metal carboxylate, a metal chelate, and zeolite (aluminosilicate) is preferably contained.

Examples of such oxygen absorbents include calcium oxide (CaO), barium oxide (BaO), magnesium oxide (MgO), strontium oxide (SrO), and lithium sulfate (Li)₂SO₄) Sodium sulfate (Na)₂SO₄) Calcium sulfate (CaSO)₄) Magnesium sulfate (MgSO)₄) Cobalt sulfate (CoSO)₄) Gallium sulfate (Ga)₂(SO₄)₃) Titanium sulfate (Ti (SO)₄)₂) Nickel sulfate (NiSO)₄) And the like.

The organic getter is not particularly limited as long as it absorbs water by a chemical reaction and does not become opaque before and after the reaction. The organometallic compound is a compound having a metal-carbon bond, a metal-oxygen bond or a metal-nitrogen bond. When water reacts with the organic metal compound, the bond is cleaved by a hydrolysis reaction to become a metal hydroxide. Depending on the metal, the metal hydroxide may be subjected to hydrolytic polycondensation after the reaction to increase the molecular weight.

As the metal of the metal alkoxide, the metal carboxylate, and the metal chelate, a metal having good reactivity with water as an organometallic compound, that is, a metal atom which is easily cleaved with various bonds by water is preferable. Specific examples thereof include aluminum, silicon, titanium, zirconium, silicon, bismuth, strontium, calcium, copper, sodium and lithium. Examples thereof include cesium, magnesium, barium, vanadium, niobium, chromium, tantalum, tungsten, chromium, indium, iron, and the like. In particular, from the viewpoint of dispersibility in a resin or reactivity with water, a drying agent of an organometallic compound having aluminum as a central metal is preferable. Examples of the organic group include unsaturated hydrocarbons such as methoxy, ethoxy, propoxy, butoxy, 2-ethylhexyl, octyl, decyl, hexyl, octadecyl, and stearyl, saturated hydrocarbons, branched unsaturated hydrocarbons, branched saturated hydrocarbons, alkoxy groups or carboxyl groups containing cyclic hydrocarbons, acetylacetonyl, β -diketo (diketonate) groups such as 2,2,6,6, -tetramethyl-3, 5-heptanedionate, and the like.

Among them, from the viewpoint of forming a sealing composition having excellent transparency, it is preferable to use an aluminum ethyl acetoacetate having 1 to 8 carbon atoms represented by the following chemical formula.

[ chemical formula 28]

(in the formula, R₅～R₈Represents an organic group containing an alkyl group, an aryl group, an alkoxy group, a cycloalkyl group, and an acyl group, each having 1 to 8 carbon atoms, and M represents a metal atom having a valence of 3. In addition, R₅～R₈The organic groups may be the same or different. )

The aluminum ethyl acetoacetate having 1 to 8 carbon atoms is sold by, for example, Kawaken Fine Chemicals Co., Ltd., Hope Chemical Co., Ltd., and can be obtained from these companies.

The oxygen absorbent is in the form of particles or powder. The average particle diameter of the oxygen absorbent may be generally set to a range of less than 20 μm, preferably 10 μm or less, more preferably 2 μm or less, and still more preferably 1 μm or less. The average particle diameter of the oxygen absorbent is preferably 0.3 to 2 μm, more preferably 0.5 to 1.0 μm, from the viewpoint of scattering properties. The average particle diameter referred to herein is an average value of particle diameters calculated from a particle size distribution measured by a dynamic light scattering method.

Polymerization inhibitors

The coating liquid for forming a fluorescent region may contain a polymerization inhibitor. The content of the polymerization inhibitor is 0.001 to 1% by mass, preferably 0.005 to 0.5% by mass, and more preferably 0.008 to 0.05% by mass based on the total amount of all polymerizable monomers. By mixing an appropriate amount of the polymerization inhibitor, a viscosity change with time can be suppressed while maintaining high curing sensitivity. On the other hand, if the amount of the polymerization inhibitor added is too large, curing failure due to polymerization inhibition or coloring of the cured product may occur, and therefore, the amount is appropriate. The polymerization inhibitor may be added at the time of producing the polymerizable monomer, or may be added to the curable composition later. Preferable examples of the polymerization inhibitor include hydroquinone, p-methoxyphenol, di-t-butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4 '-thiobis (3-methyl-6-t-butylphenol), 2' -methylenebis (4-methyl-6-t-butylphenol), N-nitrosophenylhydroxylamine cerous salt, phenothiazine, phenoxazine, 4-methoxynaphthol, 2,6, 6-tetramethylpiperidin-1-oxyl radical, 2,6, 6-tetramethylpiperidin, 4-hydroxy-2, 2,6, 6-tetramethylpiperidin-1-oxyl radical, nitrobenzene, and dimethylaniline, and p-benzoquinone, 2,6, 6-tetramethylpiperidin-1-oxyl radical are preferable, 4-hydroxy-2, 2,6, 6-tetramethylpiperidine-1-oxyl free radical and phenothiazine. These polymerization inhibitors suppress the generation of polymer impurities not only when the polymerizable monomer is produced but also when the cured composition is stored, thereby suppressing the deterioration of pattern formability during imprinting.

Light scattering particles

The fluorescent region may contain light scattering particles. Therefore, light scattering particles can be added to the coating liquid for forming a fluorescent region.

The particle size of the light scattering particles is preferably 0.10 μm or more. From the viewpoint of further improving the luminance, it is preferable that the light scattering particles are contained in the wavelength conversion layer. From the viewpoint of light scattering effect, the particle size of the light scattering particles is preferably in the range of 0.10 to 15.0. mu.m, more preferably in the range of 0.10 to 10.0. mu.m, and still more preferably in the range of 0.20 to 4.0. mu.m. In addition, in order to further improve the luminance or adjust the luminance distribution with respect to the viewing angle, two or more kinds of light scattering particles having different particle sizes may be mixed and used.

The light scattering particles may be organic particles, inorganic particles, or organic-inorganic composite particles. For example, the organic particles include synthetic resin particles. Specific examples thereof include silicone resin particles, acrylic resin particles (polymethyl methacrylate (PMMA)), nylon resin particles, styrene resin particles, polyethylene particles, urethane resin particles, and benzoguanamine particles. In the wavelength conversion layer, the refractive index of the light scattering particles is preferably different from that of the other portions from the viewpoint of the light scattering effect, and in this regard, silicone resin particles and acrylic resin particles are preferable from the viewpoint of easy availability of particles having a preferable refractive index. Further, particles having a hollow structure can also be used. Further, as the inorganic particles, particles of diamond, titanium oxide, zirconium oxide, lead carbonate, zinc oxide, zinc sulfide, antimony oxide, silicon oxide, aluminum oxide, and the like can be used, and from the viewpoint of easy availability of particles having a preferable refractive index, titanium oxide and aluminum oxide are preferable.

In order to adjust the refractive index of the fluorescent region, particles having a smaller particle size than the light scattering particles can be used as the refractive index adjuster. The particle size of the refractive index adjuster is less than 0.1. mu.m, preferably in the range of 0.01 to 0.1. mu.m.

Examples of the refractive index adjusting particles include particles of diamond, titanium oxide, zirconium oxide, lead carbonate, zinc oxide, zinc sulfide, antimony oxide, silicon oxide, aluminum oxide, and the like. Among them, particles of zirconia or silica are preferable from the viewpoint of less absorption of blue light or ultraviolet light, and particles of zirconia are preferable from the viewpoint of being able to adjust the refractive index in a small amount. Further, titanium oxide is also preferable from the viewpoint of dispersibility. The refractive index adjusting particles may be used in an amount capable of adjusting the refractive index, and the content of the refractive index adjusting particles in the light scattering layer is not particularly limited.

In addition to the above components, a release agent, an ultraviolet absorber, a light stabilizer, an anti-aging agent, a plasticizer, an adhesion promoter, a thermal polymerization initiator, a colorant, elastomer particles, a photoacid generator, a photobase generator, an alkaline compound, a flow regulator, an antifoaming agent, a dispersant, and the like may be added to the fluorescent region forming coating liquid as necessary.

The method for preparing the coating liquid for forming a fluorescent region is not particularly limited as long as it is carried out by a general procedure for preparing a curable composition.

Resin layer

The resin layer 38 is formed by applying a resin layer forming coating liquid containing the same curable composition as that for forming the above adhesive and curing the coating liquid.

The curable composition for forming the resin layer may be the same as or different from the curable composition for forming the adhesive. The curable composition for forming the resin layer may not contain a polymer dispersant.

The elastic modulus of the resin layer 38 is preferably 0.5GPa to 10GPa, more preferably 1GPa to 7GPa, and particularly preferably 3GPa to 6 GPa. When the elastic modulus of the resin layer is in this range, the resin layer can be prevented from being chipped when formed, which is preferable.

The elastic modulus of the resin layer is measured by a method exemplified in JIS K7161 and the like.

As a material for forming the resin layer 38, a compound having a photopolymerizable crosslinking group having 2 or more functions is preferable, and examples thereof include an alicyclic (meth) acrylate such as urethane (meth) acrylate and tricyclodecane dimethanol di (meth) acrylate, a hydroxyl group-containing (meth) acrylate such as pentaerythritol triacrylate, an aromatic (meth) acrylate such as modified bisphenol a di (meth) acrylate, dipentaerythritol di (meth) acrylate, 3, 4-epoxycyclohexylmethyl (meth) acrylate, 3',4' -epoxycyclohexylmethyl 3, 4-epoxycyclohexane carboxylate, bisphenol a-type epoxy compound, and the like. Among them, at least urethane (meth) acrylate and epoxy compound are preferably contained. By using a compound having a urethane bond or a polar functional group such as a hydroxyl group or a carboxyl group, the interaction between molecules can be improved. In addition, from the viewpoint of excellent adhesion between the resin layer and the fluorescent region, it is preferable to include a compound having the same polymerizable crosslinking group as that of the fluorescent region. For example, when dicyclopentyl (meth) acrylate or the like is contained in the material of the fluorescent region, the resin layer preferably contains at least a (meth) acrylate compound.

(additives)

The coating liquid for forming a resin layer may contain a photopolymerization initiator, an inorganic layered compound, scattering particles, an antioxidant, a peeling accelerator, a solvent, and the like as needed.

(photopolymerization initiator)

The curable compound forming the resin layer 38 preferably contains a photopolymerization initiator. As the photopolymerization initiator, any photopolymerization initiator can be used as long as it is a compound that generates an active species to polymerize the polymerizable compound by light irradiation. Examples of the photopolymerization initiator include a cationic polymerization initiator and a radical polymerization initiator, and they are appropriately selected depending on the material for forming the resin layer.

(scattering particles)

The coating liquid for forming the resin layer may contain scattering particles. The scattering particles include the same scattering particles as can be contained in the fluorescent region forming coating liquid.

The ratio of the volume Vp of the fluorescent region to the volume Vb of the resin layer can be any ratio, but the ratio of the volume Vp of the fluorescent region to the volume (Vp + Vb) of the entire wavelength conversion layer is preferably 0.1 ≦ Vp/(Vp + Vb) < 0.9, more preferably 0.2 ≦ Vp/(Vp + Vb) < 0.85, and particularly preferably 0.3 ≦ Vp/(Vp + Vb) < 0.8. If the volume ratio of the fluorescent region is too small, the initial luminance tends to decrease at a certain thickness, and if the volume ratio of the fluorescent region is too large, the width of the resin layer becomes short, and the strength of the resin layer may decrease. The region Vp containing the phosphor and the region Vb of the resin layer are defined as values obtained by multiplying the respective areas and thicknesses when viewed from the principal surface of the wavelength conversion member.

Substrate film-

The 1 st base material film 10 and the 2 nd base material film 20 are used to support the wavelength conversion layer, and a base material film used as a support can be used for various laminated films.

The

base films

10 and 20 preferably have gas barrier properties. The

base films

10 and 20 may be constituted only by a support having sufficient barrier properties, or may have a structure in which a barrier layer is provided on one surface of a support film.

The 1 st base film 10 and the 2 nd base film 20 preferably have a total light transmittance of 80% or more, more preferably 85% or more, in the visible light region. The visible light region is a wavelength region of 380 to 780nm, and the total light transmittance is an average value of light transmittance in the visible light region.

The

substrate films

10 and 20 are preferably flexible belt-like supports transparent to visible light. Here, the term "transparent to visible light" means that the light transmittance in the visible light region is 80% or more, preferably 85% or more. The light transmittance used as a transparent scale can be calculated by measuring the total light transmittance and the amount of scattered light using an integrating sphere type light transmittance measuring apparatus, which is a method described in JIS-K7105, and subtracting the diffuse transmittance from the total light transmittance. As for the support having flexibility, refer to paragraphs 0046 to 0052 of Japanese patent application laid-open No. 2007 and 290369 and paragraphs 0040 to 0055 of Japanese patent application laid-open No. 2005 and 096108.

The oxygen permeability of the 1 st substrate film 10 and the 2 nd substrate film 20 is preferably 1.00 cc/(m)²Day atm) or less. The oxygen transmission rate is more preferably 0.1 cc/(m)²Day atm) or less, and more preferably 0.01 cc/(m)²Day atm) or less, and particularly preferably 0.001 cc/(m)²Day atm) or less. Here, the oxygen transmission rate is a value measured by using an oxygen transmission rate measuring apparatus (manufactured by MOCON inc., OX-TRAN 2/20: trade name) under the conditions of a measuring temperature of 23 ℃ and a relative humidity of 90%.

The 1 st substrate film 10 and the 2 nd substrate film 20 preferably have a function of blocking moisture (water vapor) in addition to a gas barrier function of blocking oxygen. The moisture permeability (water vapor transmission rate) of the 1 st base film 10 and the 2 nd base film 20 is preferably 0.10 g/(m)²Day atm) or less, more preferably 0.01 g/(m)²Day atm) or less.

(supporting film)

The support film is preferably a flexible belt-like support transparent to visible light. Here, the term "transparent to visible light" means that the light transmittance in the visible light region is 80% or more, preferably 85% or more. The light transmittance used as a transparent scale can be calculated by measuring the total light transmittance and the amount of scattered light using an integrating sphere type light transmittance measuring apparatus, which is a method described in JIS-K7105, and subtracting the diffuse transmittance from the total light transmittance. As for the support having flexibility, refer to paragraphs 0046 to 0052 of Japanese patent application laid-open No. 2007 and 290369 and paragraphs 0040 to 0055 of Japanese patent application laid-open No. 2005 and 096108.

The support film preferably has barrier properties against oxygen and moisture. Preferable examples of such a support film include a polyethylene terephthalate film, a film containing a polymer having a cyclic olefin structure, and a polystyrene film.

The average film thickness of the support film is preferably 10 μm or more and 500 μm or less, more preferably 20 μm or more and 400 μm or less, and still more preferably 30 μm or more and 300 μm or less, from the viewpoint of impact resistance of the wavelength conversion member and the like. In the mode of increasing the retroreflection of light, such as the case of reducing the concentration of quantum dots contained in the wavelength conversion layer 30 or the case of reducing the thickness of the wavelength conversion layer 30, the absorptance of light with a wavelength of 450nm is preferably lower, and therefore the average film thickness of the support film is preferably 40 μm or less, and more preferably 25 μm or less, from the viewpoint of suppressing the decrease in luminance.

Further, the in-plane retardation Re (589) of the support film at a wavelength of 589nm is preferably 1000nm or less. More preferably 500nm, and still more preferably 200nm or less.

When the presence of foreign matter or defect is checked after the wavelength conversion member is manufactured, the foreign matter or defect is easily found by disposing two polarizing plates at the extinction position and observing the polarizing plates with the wavelength conversion member interposed therebetween. When Re (589) of the support is in the above range, foreign matter and defects are more likely to be found in the inspection using the polarizing plate, which is preferable.

Here, Re (589) can be measured by causing light having an input wavelength of 589nm to enter in the film normal direction using AxoScan OPMF-1(OPTO SCIENCE, inc.).

(Barrier layer)

The 1 st substrate film 10 and the 2 nd substrate film 20 preferably include a barrier layer including at least one inorganic layer formed in contact with the surface of the support film on the wavelength conversion layer 30 side. As the barrier layer, at least one inorganic layer and at least one organic layer may be contained. When a plurality of layers are stacked in this manner, barrier properties can be further improved, and therefore, the light resistance is preferably improved. On the other hand, since the light transmittance of the base film tends to decrease as the number of layers to be laminated increases, it is preferable to increase the number of layers within a range in which good light transmittance can be maintained.

The barrier layer preferably has a total light transmittance of 80% or more and an oxygen transmittance of 1.00 cc/(m) in the visible light region²Day atm) or less.

The oxygen transmission rate of the barrier layer is more preferably 0.1 cc/(m)²Day atm) or less, and particularly preferably 0.01 cc/(m)²Day atm) or less, more preferably 0.001 cc/(m)²Day atm) or less.

The lower the oxygen transmittance is, the more preferable is the higher is the total light transmittance in the visible light region.

Inorganic layer-

The inorganic layer is a layer containing an inorganic material as a main component, preferably a layer containing 50% by mass or more, more preferably 80% by mass or more, particularly 90% by mass or more of the inorganic material, and preferably a layer formed only of the inorganic material.

The inorganic layer is preferably a layer having a gas barrier function of blocking oxygen. Specifically, the oxygen permeability of the inorganic layer is preferably 1.00 cc/(m)²Day atm) or less. The oxygen permeability of the inorganic layer can be determined by attaching the wavelength conversion layer to a detection portion of an oxygen concentration meter manufactured by ORBISPHERE Laboratories, and converting the oxygen permeability from the equilibrium oxygen concentration value. The inorganic layer also preferably has a function of blocking water vapor.

2 or more than 3 inorganic layers may be included in the barrier layer.

The thickness of the inorganic layer may be 1 to 500nm, preferably 5 to 300nm, and particularly preferably 10 to 150 nm. This is because, when the film thickness of the inorganic layer is within the above range, a good barrier property can be achieved, and reflection in the inorganic layer can be suppressed, so that a laminated film having higher light transmittance can be provided.

The inorganic material constituting the inorganic layer is not particularly limited, and various inorganic compounds such as metals, inorganic oxides, nitrides, and nitride oxides can be used. As the element constituting the inorganic material, silicon, aluminum, magnesium, titanium, tin, indium, and cerium are preferable, and one or two or more of these may be contained. Specific examples of the inorganic compound include silicon oxide, silicon oxide nitride, aluminum oxide, magnesium oxide, titanium oxide, tin oxide, indium oxide alloy, silicon nitride, aluminum nitride, and titanium nitride. Further, as the inorganic layer, a metal film such as an aluminum film, a silver film, a tin film, a chromium film, a nickel film, or a titanium film may be provided.

Among the above materials, the inorganic layer having a barrier property is particularly preferably an inorganic layer containing at least one compound selected from the group consisting of silicon nitride, silicon oxynitride, silicon oxide, and aluminum oxide. This is because the inorganic layer containing these materials has good adhesion to the organic layer, and therefore even when pinholes are present in the inorganic layer, the organic layer can effectively fill the pinholes, and breakage can be suppressed, and furthermore, when the inorganic layer is laminated, an extremely good inorganic layer film can be formed, and barrier properties can be further improved. Further, silicon nitride is most preferable from the viewpoint of suppressing light absorption in the barrier layer.

The method of forming the inorganic layer is not particularly limited, and various film-forming methods can be used, for example, which can evaporate or scatter the film-forming material and deposit the film-forming material on the deposition surface.

Examples of the method for forming the inorganic layer include a vacuum vapor deposition method in which an inorganic material such as an inorganic oxide, an inorganic nitride oxide, or a metal is heated and deposited; an oxidation reaction vapor deposition method in which an inorganic material is used as a raw material and vapor deposition is performed by introducing oxygen gas and oxidizing the introduced oxygen gas; a sputtering method in which an inorganic material is used as a target material and sputtering is performed by introducing argon gas and oxygen gas to perform evaporation; physical Vapor Deposition methods such as ion Plating (PVD) in which an inorganic material is heated by a plasma beam generated by a plasma gun to be deposited; a plasma Chemical Vapor Deposition method (CVD method) using an organic silicon compound as a raw material for producing a Vapor deposited film of silicon oxide.

Organic layer-

The organic layer is a layer containing an organic material as a main component, and means a layer in which the organic material occupies preferably 50% by mass or more, more preferably 80% by mass or more, and particularly preferably 90% by mass or more.

As the organic layer, paragraphs 0020 to 0042 of Japanese patent application laid-open No. 2007 and 290369 and paragraphs 0074 to 0105 of Japanese patent application laid-open No. 2005 and 096108 can be cited. In addition, the organic layer preferably contains a pyridoxine (cardo) polymer within a range satisfying the above adhesion force conditions. This is because the adhesion between the organic layer and the adjacent layer, particularly the inorganic layer, is also good, and further excellent gas barrier properties can be achieved. As for the details of the pyridoxine polymer, reference can be made to paragraphs 0085 to 0095 of the above-mentioned Japanese patent application laid-open No. 2005-096108.

The film thickness of the organic layer is preferably in the range of 0.05 to 10 μm, and more preferably in the range of 0.5 to 10 μm. When the organic layer is formed by a wet coating method, the film thickness of the organic layer is in the range of 0.5 to 10 μm, preferably 1 to 5 μm. When the coating layer is formed by a dry coating method, the thickness is preferably in the range of 0.05 to 5 μm, and more preferably in the range of 0.05 to 1 μm. This is because when the film thickness of the organic layer formed by the wet coating method or the dry coating method is in the above range, the adhesion to the inorganic layer can be further improved.

For other details of the inorganic layer and the organic layer, reference can be made to the descriptions of the above-mentioned Japanese patent application laid-open Nos. 2007 and 290369, 2005 and 096108, and US2012/0113672A 1.

In the wavelength conversion member, the organic layer may be laminated between the support film and the inorganic layer as a base layer of the inorganic layer, or may be laminated between the inorganic layer and the wavelength conversion layer as a protective layer of the inorganic layer. When two or more inorganic layers are provided, the organic layer may be stacked between the inorganic layers.

(layer having irregularities)

The

substrate films

10 and 20 may be provided with an irregularity imparting layer for imparting an irregularity structure on a surface opposite to the surface on the wavelength conversion layer 30 side. It is preferable that the

substrate films

10 and 20 have the unevenness-imparting layer because the blocking property and the smoothness of the substrate films can be improved. The unevenness-imparting layer is preferably a layer containing particles. Examples of the particles include inorganic particles such as silica, alumina, and metal oxide, and organic particles such as crosslinked polymer particles. The unevenness-imparting layer is preferably provided on the surface of the base film on the side opposite to the wavelength conversion layer, but may be provided on both surfaces.

< method for manufacturing wavelength conversion member >

Next, an example of a manufacturing process of the wavelength conversion member according to the embodiment of the present invention configured as described above will be described with reference to fig. 8 to 9.

(coating liquid preparation Process)

In the first coating liquid preparation step 1, a coating liquid for forming a fluorescent region containing quantum dots (or quantum rods) as a phosphor is prepared. Specifically, the coating liquid for forming a fluorescent region is prepared by mixing the respective components such as the quantum dots, the curable compound, the polymer dispersant, the polymerization initiator, and the silane coupling agent dispersed in the organic solvent using a pot or the like. The coating liquid for forming a fluorescent region may not contain an organic solvent.

In the 2 nd coating liquid preparation step, a coating liquid for forming a resin layer filled between the fluorescent regions is prepared.

(resin layer Forming step)

Next, a coating liquid for forming a resin layer is applied on the 1 st base material film 10, a mold (die) having a concave-convex pattern is pressed against the applied coating liquid for forming a resin layer to form a predetermined pattern having a concave portion, and the coating liquid for forming a resin layer is cured, thereby forming a laminated film 59 in which a resin layer 38 having a plurality of concave portions is laminated on the 1 st base material film 10 as shown in fig. 8.

In this case, by providing a fine uneven shape on the surface of a mold (die) having an uneven pattern, the surface roughness Ra of the resin layer after the formation of the recessed portions can be set within a predetermined range.

(fluorescent region Forming step and No. 2 substrate film laminating step)

Next, a fluorescent region forming coating liquid is applied to the recessed portion of the resin layer 38 of the laminated film 59, and before the fluorescent region forming coating liquid is cured and after the 2 nd base material film 20 is bonded, the fluorescent region 35 is formed by curing the fluorescent region forming coating liquid, thereby producing a wavelength conversion member in which the 1 st base material film 10, the wavelength conversion layer 30, and the 2 nd base material film 20 are laminated.

The curing treatment in the fluorescent region forming step and the resin layer forming step may be appropriately selected from thermosetting, ultraviolet light curing, and the like, depending on the coating liquid.

When the resin layer 38 is cured by ultraviolet light-curing, the irradiation amount of the ultraviolet light is preferably 100 to 10000mJ/cm²。

When the resin layer 38 is cured by heat curing, it is preferably heated to 20 to 100 ℃.

(cutting processing)

The obtained wavelength conversion member is cut (cut) with a cutter as necessary.

In addition, the wavelength conversion member may be produced by continuously performing the above steps by a so-called roll-to-roll (RtoR), or by performing the steps in a so-called single sheet manner using a base film in a cut sheet form.

Here, a method of forming a plurality of concave portions (concave-convex patterns) on the coating liquid for the resin layer applied to the 1 st base film 10 will be specifically described.

As the pattern formation, as described above, the following method can be used: a mold (die) having an uneven pattern is pressed against the coating liquid for the resin layer applied to the base film to form the uneven pattern.

Further, the pattern can be formed by an ink jet method or a dropping method.

Here, as the mold, a mold having a pattern to be transferred is used. The pattern on the mold can be formed by, for example, photolithography, electron beam lithography, or the like according to a desired processing accuracy, but the method of forming the mold pattern is not particularly limited.

The light-transmitting mold material is not particularly limited as long as it has a predetermined strength and durability. Specifically, examples thereof include a light-transparent resin such as glass, quartz, PMMA, and polycarbonate resin, a transparent metal vapor-deposited film, a flexible film such as polydimethylsiloxane, a photo-curable film, and a metal film such as SUS.

On the other hand, the non-light-transmissive mold material is not particularly limited as long as it has a predetermined strength. Specifically, examples thereof include ceramic materials, vapor-deposited films, magnetic films, reflective films, metal substrates such as Ni, Cu, Cr, and Fe, and substrates such as SiC, silicon nitride, polysilicon, silicon oxide, and amorphous silicon. The shape of the mold is not particularly limited, and may be a plate-shaped mold or a roll-shaped mold. The roll-shaped mold is particularly suitable for a case where continuous productivity of transfer printing is required.

In order to improve the releasability of the curable composition from the mold surface, a mold subjected to a mold release treatment may be used. Examples of such a mold include a mold coated with a material having excellent water and oil repellency, specifically, a mold coated with Polytetrafluoroethylene (PTFE) or diamond-like carbon (DLC) by Physical Vapor Deposition (PVD) or Chemical Vapor Deposition (CVD), a mold treated with a silane coupling agent such as silicon or fluorine, and a release agent commercially available from DAIKIN INDUSTRIES, OPTOOL DSX manufactured by ltd, Novec EGC-1720 manufactured by Sumitomo 3M Limited, or the like can be suitably used.

Examples of the method for forming the uneven pattern using the mold include, specifically, a hot embossing method in which a mold is pressed against a resin layer applied to a substrate film and cured, in a state in which the resin layer or the mold is heated, to form the uneven pattern; a photo-imprint method in which a mold (die) having an uneven pattern is pressed against a coating liquid for a resin layer applied to a base film, and then the resin layer is cured by light to form the uneven pattern; a melt molding method for forming a concave-convex pattern, and the like. Among them, the photo-embossing method is preferable from the viewpoint of excellent production speed and less equipment investment.

When performing photo-imprint lithography, it is generally preferred to perform at a mold pressure of 10 atmospheres or less. By setting the mold pressure to 10 atmospheres or less, the mold and the substrate are not easily deformed, and the pattern accuracy tends to be improved. Further, it is also preferable from the viewpoint that the pressurization is small and the apparatus tends to be downsized. The mold pressure is preferably selected in a range where the residual film of the curable composition at the convex portion of the mold is reduced, so that the uniformity of mold transfer can be ensured.

The irradiation amount of the light irradiation in the curing part may be sufficiently larger than the irradiation amount required for curing. The irradiation amount required for curing can be determined as appropriate by examining the amount of unsaturated bonds consumed in the curable composition or the instantaneous adhesive force of the cured film.

In addition, in the case of the photo imprint lithography, the substrate temperature at the time of light irradiation is usually room temperature, but light irradiation may be performed while heating is performed to improve reactivity. As the pre-stage of the light irradiation, if the vacuum state is set in advance, it is effective to prevent the mixing of bubbles, suppress the decrease in reactivity due to the mixing of oxygen, and improve the adhesion between the mold and the curable composition, and therefore, the light irradiation can be performed in the vacuum state. In the pattern forming method, the preferable degree of vacuum at the time of light irradiation is 10 ^-1Pa to 1 atmosphere.

The light used for curing the curable composition is not particularly limited, and examples thereof include high-energy ionizing radiation, light having a wavelength in the near-ultraviolet, far-ultraviolet, visible, infrared, or the like, and radiation. As the high-energy ionizing radiation source, for example, an electron beam accelerated by an accelerator such as a kocroft (Cockcroft) type accelerator, a Van der Graaff (Van de Graaff) type accelerator, a linear accelerator, an electron induction accelerator, or a cyclotron is industrially most conveniently and economically used, and radiation such as gamma rays, X rays, α rays, neutron beams, and proton beams emitted from radioisotopes, atomic furnaces, and the like can be used. Examples of the ultraviolet source include an ultraviolet fluorescent lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a xenon lamp, a carbon arc lamp, a solar lamp, and an LED (light emitting diode). Examples of the radiation include microwave and EUV (extreme ultraviolet). Further, a laser used for semiconductor microfabrication, such as an LED, a semiconductor laser, or a KrF excimer laser of 248nm or an ArF excimer laser of 193nm, can also be preferably used in the present invention. These lights may be monochromatic lights (monochrome light) or different lights of multiple wavelengths (mixed lights).

While performing exposurePreferably, the exposure illuminance is set at 1mW/cm²～1000mW/cm²The range of (1). By setting at 1mW/cm²As described above, the exposure time can be shortened, and thus the productivity is improved by setting the exposure time to 1000mW/cm²Hereinafter, the deterioration of the characteristics of the permanent film due to the occurrence of side reactions tends to be suppressed, and therefore, the method is preferable. The exposure amount is preferably set at 5mJ/cm²～10000mJ/cm²The range of (1). When less than 5mJ/cm²In the case of this method, the exposure range is narrowed, and photocuring becomes insufficient, so that problems such as adhesion of an unreacted product to a mold tend to occur. On the other hand, if it exceeds 10000mJ/cm²There is a possibility that the composition may be decomposed to cause deterioration of the permanent film. In addition, in order to prevent the radical polymerization from being inhibited by oxygen at the time of exposure, an inert gas such as nitrogen or argon may be discharged to control the oxygen concentration to less than 100 mg/L.

The curing section may include a step of curing the curable composition by light irradiation, and then further curing by applying heat if necessary. The heat for heat curing after light irradiation is preferably 80 to 280 ℃, more preferably 100 to 200 ℃. The time for applying heat is preferably 5 to 60 minutes, and more preferably 15 to 45 minutes.

The uneven pattern formed on the resin layer can take any form, and examples thereof include a lattice-like mesh pattern in which the opening shape of the concave portions is a regular quadrangle or a rectangle, a honeycomb pattern in which the concave portions are regular hexagons, a sea-island pattern in which the concave portions are circular, a composite pattern in which the concave portions are a combination of regular pentagons and regular hexagons, a combination of circles having different diameters, and a pattern in which the sizes of hexagons have an in-plane distribution.

Among them, when the resin layer is formed by the photo-imprint method, regular polygons such as squares and regular hexagons and circular patterns are preferable from the viewpoint of suppressing the wall breakage when the resin layer is peeled from the mold, shortening the entrance (entrance) distance, and the like, and regular hexagons are more preferable from the viewpoint of improving the filling factor (area ratio) of the fluorescent region.

The entrance distance is a distance from the cut end surface to the vertical direction when the wavelength conversion member is cut so as to cross the fluorescence region, and is a distance at which a change in chromaticity or a decrease in luminance can be confirmed by visual observation.

In the above example, the step of curing the resin layer is performed in a state where the mold is attached, but may be performed after the mold is detached. Preferably, the reaction is carried out in a state where the mold is tightly adhered.

When the hot stamping method is performed, it is generally preferable to perform the hot stamping method at a mold pressure in the range of 0.1 to 100 MPa. The temperatures of the mold and the resin layer are preferably set to predetermined ranges, and in general, the mold temperature is set to a temperature equal to or higher than the glass transition temperature (Tg) of the resin layer and the substrate temperature is set to a temperature lower than the mold temperature in many cases.

In the case of the melt molding method, the resin to be molded is heated to a temperature not lower than the melting point, and then immediately after the resin in a molten state (melt) is poured between the mold and the base film, the resin is pressed and cooled to produce the resin film. Specific examples of materials suitable for the resin layer 38 in the melt molding process include polyester resins such as polyvinyl alcohol (PVA), polyethylene-vinyl alcohol copolymer (EVOH), polyvinylidene chloride (PVDC), polyvinylidene fluoride (PVDF), and polyethylene terephthalate (PET). Among them, from the viewpoint of excellent transparency and heat and light resistance, (modified) polyvinyl alcohol is preferable, and polyethylene-vinyl alcohol copolymer (EVOH) is particularly preferable.

In order to secure adhesion to the base film forming the resin layer, an anchor coat layer (anchor coat layer) may be provided on the base film. The material of the anchor coat layer may be appropriately selected depending on the material of the resin layer and the substrate film, and for example, when the resin layer is EVOH and the substrate film is PET, examples of the material of the anchor coat layer include urethane compounds, polyethyleneimine compounds, polybutadiene compounds, and (modified) polyolefin compounds, and the anchor coat layer material of urethane compounds and (modified) polyolefin compounds is most preferable from the viewpoint of excellent water resistance and adhesion. Specific examples of the commercial products include EL-530A/B manufactured by Toyo-Morton, Ltd, TAKELAC A/TAKENATE A series manufactured by Mitsui Chemicals, Inc., ADMER series, and Unistole series.

"backlight unit"

A backlight unit provided with a wavelength conversion member of the present invention will be described with reference to the accompanying drawings. Fig. 10 is a schematic diagram showing a structure of a side-edge-light (side edge) type backlight unit as an example of the backlight unit.

As shown in fig. 10, the backlight unit 102 includes: a planar light source 101C emitting primary light (blue light L)_B) A light guide plate 101B that guides and emits the primary light emitted from the light source 101A; a wavelength conversion member 100 of the present invention is provided on a planar light source 101C; a reflection plate 102A disposed opposite to the wavelength conversion member 100 with the planar light source 101C interposed therebetween; and a retroreflective member 102B. Fig. 10 shows the reflection plate 102A, the light guide plate 101B, the wavelength conversion member 100, and the retroreflective member 102B separated from each other, but these members are not optically adhered to each other and can be laminated in practice.

The wavelength conversion member 100 converts the primary light L emitted from the planar light source 101C_BEmits fluorescence as excitation light, and emits secondary light (green light L) composed of the fluorescence_GRed light L_R) And the primary light L transmitted through the wavelength conversion member 100_B. For example, the wavelength conversion member 100 is a wavelength conversion member in which a wavelength conversion layer containing the blue light L is sandwiched between a 1 st base material film and a 2 nd base material film _BEmits green light L by the irradiation of_GAnd emits red light L_RThe quantum dot of (1).

In fig. 10, L emitted from the wavelength conversion member 100_B、L_G、L_RWhen the light enters the retroreflective member 102B, the incident light is repeatedly reflected between the retroreflective member 102B and the reflective plate 102A and passes through the wavelength conversion member 100 a plurality of times. As a result, a sufficient amount of excitation light (blue light L) is emitted from the wavelength conversion member 100_B) Is absorbed by the phosphor 31 (quantum dot here) in the wavelength conversion layer 30 to emit a desired amount of fluorescence (L)_G、L_R) White light L is realized from the retroreflective member 102B_WAnd is emitted.

From the viewpoint of achieving high luminance and high color reproducibility, a backlight unit using a multi-wavelength light source is preferably used as the backlight unit. For example, it is preferable that the red light emitting element emits blue light having an emission center wavelength in a wavelength range of 430 to 480nm and having a peak of an emission intensity of 100nm or less at full width at half maximum, green light having an emission center wavelength in a wavelength range of 500 to 600nm and having a peak of an emission intensity of 100nm or less at full width at half maximum, and red light having an emission center wavelength in a wavelength range of 600 to 680nm and having a peak of an emission intensity of 100nm or less at full width at half maximum.

From the viewpoint of further improving the luminance and color reproducibility, the wavelength range of the blue light emitted from the backlight unit is more preferably 440nm to 460 nm.

From the same viewpoint, the wavelength range of the green light emitted from the backlight unit is preferably 520nm to 560nm, and more preferably 520nm to 545 nm.

From the same viewpoint, the wavelength range of red light emitted from the backlight unit is more preferably 610nm to 650 nm.

From the same viewpoint, the full width at half maximum of each emission intensity of the blue light, the green light, and the red light emitted from the backlight unit is preferably 80nm or less, more preferably 50nm or less, even more preferably 40nm or less, and even more preferably 30nm or less. Among these, the full width at half maximum of the emission intensity of blue light is particularly preferably 25nm or less.

In the above, the light source 101A is, for example, a blue light emitting diode that emits blue light having an emission center wavelength in a wavelength range of 430nm to 480nm, but an ultraviolet light emitting diode that emits ultraviolet light may be used. As the light source 101A, a laser light source or the like can be used in addition to the light emitting diode. When a light source that emits ultraviolet light is provided, the wavelength conversion layer (wavelength conversion layer) of the wavelength conversion member may include a phosphor that emits blue light, a phosphor that emits green light, and a phosphor that emits red light by irradiation of ultraviolet light.

As shown in fig. 10, the planar light source 101C may be a planar light source including a light source 101A and a light guide plate 101B that guides and emits the primary light emitted from the light source 101A, or may be a planar light source in which the light source 101A is arranged in a planar shape parallel to the wavelength conversion member 100 and a diffusion plate is provided instead of the light guide plate 101B. The former planar light source is generally called a side light (edge light) system, and the latter planar light source is generally called a direct type system.

In addition, although the present embodiment has been described using a planar light source as the light source, a light source other than a planar light source may be used as the light source.

(Structure of backlight Unit)

As the configuration of the backlight unit, the edge light type in which a light guide plate, a reflection plate, or the like is used as a constituent member is described in fig. 10, but the direct type may be used. As the light guide plate, a known light guide plate can be used without any limitation.

The reflecting plate 102A is not particularly limited, and known reflecting plates can be used, and are described in japanese patent No. 3416302, japanese patent No. 3363565, japanese patent No. 4091978, japanese patent No. 3448626, and the like, and the contents of these are incorporated in the present invention.

The retroreflective member 102B may be composed of a known diffusion plate or diffusion sheet, prism sheet (e.g., BEF series manufactured by Sumitomo 3M Limited), light guide, or the like. The structure of the retroreflective member 102B is described in japanese patent No. 3416302, japanese patent No. 3363565, japanese patent No. 4091978, japanese patent No. 3448626, and the contents of these publications are incorporated in the present invention.

The backlight unit of the present invention can be preferably used as a backlight for a liquid crystal display device.

Examples

The present invention will be described in more detail with reference to examples. The materials, amounts used, ratios, processing contents, processing steps and the like shown in the following examples can be appropriately modified without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited to the specific examples shown below.

[ example 1]

< manufacture of wavelength converting Member >

A wavelength conversion member having a wavelength conversion layer was produced using a coating liquid containing quantum dots as a phosphor.

(substrate film)

As the 1 st base film and the 2 nd base film, a polyethylene terephthalate (PET) film (TOYOBO co., ltd., trade name "Cosmoshine (registered trademark) a 4300" having a thickness of 50 μm) was used.

(formation of resin layer)

The following curable composition 1 was prepared, and after filtration through a polypropylene filter having a pore size of 0.2 μm, the mixture was dried under reduced pressure for 30 minutes, thereby obtaining a coating liquid a for forming a resin layer.

Curable composition 1-

78.4 parts by mass of dicyclopentanyl acrylate (FA-513AS (manufactured by Hitachi Chemical Co., Ltd.))

Dicidol diacrylate (A-DCP (Shin-Nakamura Chemical Co., Ltd.)) 20.0 parts by mass

0.2 part by mass of a photopolymerization initiator (Irgacure TPO (BASF co., ltd.))

Formation of a resin layer

Using a roll-to-roll manufacturing apparatus, coating liquid a for forming a resin layer was applied on the 1 st base film, and the recesses were transferred, followed by photocuring to form a resin layer 38 having a plurality of recesses.

Here, the recesses were formed in a square lattice pattern of 250 μm × 250 μm, the depth of the recesses was 40 μm, and the width between the recesses was 50 μm. The surface roughness Ra of the resin layer after production was adjusted to 1 μm by imparting a fine uneven shape to the mold of the transfer recessed portion.

In addition, 2000mJ/cm was irradiated from the 1 st substrate film side by using a 160W/cm air-cooled metal halide lamp (EYE GRAPHICS Co., Ltd.) for photocuring ²The resin layer is cured by the ultraviolet rays of (1).

(formation of fluorescent region and sticking of No. 2 base film)

The following curable composition 2 was prepared, and after filtration through a polypropylene filter having a pore size of 0.2 μm, the mixture was dried under reduced pressure for 30 minutes, thereby obtaining a coating liquid a for forming a fluorescent region.

Curable composition 2-

The quantum dot concentration of the toluene dispersion of quantum dots 1 and quantum dots 2 was 3 mass%.

The quantum dot 1(INP530-100, NN-LABS, llc.) is a core/shell type quantum dot whose core is made of INP and whose shell is made of ZnS, and has an emission center wavelength of 530 nm.

The quantum dot 2(INP620-100, NN-LABS, llc.) is a core/shell type quantum dot whose core is made of INP and whose shell is made of ZnS, and has an emission center wavelength of 620 nm.

Application of coating liquid for forming fluorescent region and sticking of substrate film

Using a roll-to-roll manufacturing apparatus, a wavelength conversion member was produced by applying a fluorescent region-forming coating liquid a on a resin layer having a plurality of concave portions, filling the concave portions with the coating liquid a, bonding a 2 nd base material film, and then photocuring the base material film to form wavelength conversion layers having fluorescent regions formed in the plurality of concave portions of the resin layer.

In addition, 2000mJ/cm was irradiated from the 1 st substrate film side by using a 160W/cm air-cooled metal halide lamp (EYE GRAPHICS Co., Ltd.) for photocuring ²The fluorescent region was cured by ultraviolet rays, and further heated at 80 ℃ for 10 minutes.

The thickness of the wavelength conversion layer of the obtained wavelength conversion member was 50 μm.

Sample 1 in which a cured layer was formed on a glass substrate under the same composition and curing conditions as those of the resin layer included in the wavelength conversion member produced in example 1 was prepared. Similarly, sample 2 in which a cured layer was formed on a glass substrate under the same composition and curing conditions as those of the fluorescent region included in the wavelength conversion member produced in example 1 was prepared.

Using each sample, the refractive index of the cured layer on the glass substrate in the in-plane direction and the thickness direction for a wavelength of 550nm was measured by a multi-wavelength abbe refractometer DR-M2 manufactured by ATAGO CO, ltd.

The refractive index of the resin layer (sample 1) was 1.45. The refractive index of the fluorescent region (sample 2) was 1.55. That is, the refractive index difference Δ n between the resin layer and the fluorescent region was 0.1.

Comparative example 1

A wavelength conversion member was produced in the same manner as in example 1, except that a fluorescent region was formed in a layer-like manner on the resin layer having no recessed portion.

Specifically, after coating liquid a for forming a resin layer was applied on the 1 st base film, a rough surface was transferred to the coating film using a flat plate-like mold having a surface roughness Ra of 1, and the coating film was photocured to form a resin layer.

Next, after the fluorescent region-forming coating liquid a was applied to the formed resin layer, the 2 nd base material film was pasted and photocured to form a wavelength conversion layer having a layered fluorescent region formed on the resin layer, thereby producing a wavelength conversion member.

The thickness of the resin layer was set to 10 μm, and the thickness of the fluorescent region was set to 40 μm.

Comparative example 2

A wavelength conversion member was produced in the same manner as in example 1, except that the resin layer was not roughened.

[ example 2]

A wavelength converting member was produced in the same manner as in example 1, except that a coating liquid b for forming a fluorescent region, which was obtained by preparing curable composition 3 described below as a coating liquid for forming a fluorescent region, filtering the coating liquid with a polypropylene filter having a pore size of 0.2 μm, and drying the filtered coating liquid for 30 minutes under reduced pressure, was used.

In addition, the refractive index of the formed fluorescent region was 1.95. Therefore, the refractive index difference Δ n between the resin layer and the fluorescent region is 0.5.

Curable composition 3-

Examples 3 and 4 and comparative examples 3 to 5

A wavelength conversion member was produced in the same manner as in example 2, except that the surface roughness Ra of the resin layer was changed to the values shown in table 2, and the thickness of the wavelength conversion layer was set to 40 μm.

[ example 5]

A wavelength conversion member was produced in the same manner as in example 2, except that a coating liquid B for forming a resin layer, which was obtained by further adding 20 parts by mass of light-scattering particles (Tospearl 120(Momentive Performance Materials Inc.), to the coating liquid a, preparing the curable composition 4 described below, filtering the mixture with a polypropylene filter having a pore size of 0.2 μm, and drying the mixture under reduced pressure for 30 minutes, was used as a coating liquid B for forming a resin layer, a coating liquid c for forming a fluorescent region, which was obtained by adding 20 parts by mass of light-scattering particles, was used as a coating liquid c for forming a fluorescent region, and the thickness of the wavelength conversion layer was set to 30 μm.

The refractive index of the formed resin layer was 1.45, and the refractive index of the fluorescent region was 1.95. Therefore, the refractive index difference Δ n between the resin layer and the fluorescent region is 0.5.

Curable composition 4-

Comparative example 6

A wavelength conversion member was produced in the same manner as in example 5, except that the resin layer was not roughened.

[ example 6]

A wavelength conversion member was produced in the same manner as in example 5, except that coating liquid a was used as the coating liquid for forming the resin layer, and coating liquid d for forming the fluorescent region, which was obtained by further adding 20 parts by mass of light scattering particles (Tospearl 120(Momentive Performance Materials Inc.)) to coating liquid c, was used as the coating liquid for forming the fluorescent region.

[ example 7]

A wavelength converting member was produced in the same manner as in example 6, except that coating liquid B was used as the coating liquid for forming a resin layer.

Comparative example 7

A wavelength conversion member was produced in the same manner as in example 6, except that the resin layer was not roughened.

[ example 8]

A wavelength conversion member was produced in the same manner as in example 7, except that the substrate film B produced as follows was used as the 1 st substrate film and the 2 nd substrate film.

(preparation of base Material film B)

A base film B was produced by forming an organic layer and an inorganic layer in this order on one surface side of a support film using a polyethylene terephthalate (PET) film (TOYOBO co., ltd., product name, "Cosmoshine (registered trademark) a 4300" having a thickness of 50 μm) as the support film in the following procedure.

Formation of an organic layer

Trimethylolpropane triacrylate (product name "TMPTA", manufactured by DAI-CELL-ALLNEX ltd.) and a photopolymerization initiator (product name "ESACURE (registered trademark) KTO 46", manufactured by LAMBERTI) were prepared, and the components were weighed so that the mass ratio thereof was 95:5, and dissolved in methyl ethyl ketone to prepare a solution having a solid content of 15%The coating liquid of (1). The coating liquid was roll-to-roll coated on a PET film using a die coater, and passed through a drying zone at 50 ℃ for 3 minutes. Then, ultraviolet rays were irradiated under a nitrogen atmosphere (cumulative dose: about 600 mJ/cm) ²) The film was cured by UV curing and wound up. The thickness of the organic layer formed on the support was 1 μm.

Formation of an inorganic layer

Next, an inorganic layer (silicon nitride layer) was formed on the surface of the organic layer using a roll-to-roll CVD (chemical vapor deposition) apparatus. As the source gas, silane gas (flow rate 160sccm), ammonia gas (flow rate 370sccm), hydrogen gas (flow rate 590sccm), and nitrogen gas (flow rate 240sccm) were used. As the power source, a high-frequency power source of a frequency of 13.56MHz was used. The film forming pressure was 40Pa, and the film thickness was 50 nm. In this manner, the base material film B in which the inorganic layer is laminated on the surface of the organic layer formed on the support film was produced.

< evaluation item >

The color tones of the wavelength conversion members produced in examples and comparative examples were measured as follows, and the color reproducibility was evaluated.

(measurement of color tone)

A commercial tablet pc terminal (product name "binder (registered trademark) Fire HDX 7", manufactured by amazon.com, inc., hereinafter sometimes abbreviated as binder Fire HDX 7.) having a blue light source in the backlight unit was disassembled, and the backlight unit was taken out. The wavelength converting member of the example or the comparative example cut out in a rectangular shape was assembled in place of the wavelength converting Film QDEF (Quantum Dot Enhancement Film) assembled in the backlight unit, and two optical sheets used in the tablet terminal were stacked thereon. Thus, a backlight unit was fabricated.

The manufactured backlight unit was lit, and chromaticity (CIEx, y) was measured at 9 points in the plane using a luminance meter (trade name "SR 3", manufactured by topocon CORPORATION) provided at a position 520mm in the vertical direction with respect to the light emitting surface of the backlight unit, and an average value was calculated.

Based on the measured values, evaluation was performed according to the following criteria.

A: satisfying x is 0.21-0.23 and y is 0.24-0.26.

B: satisfies 0.19. ltoreq. x < 0.24 and 0.22. ltoreq. y < 0.27, and is not included in the backlight unit of A.

C: satisfying 0.15. ltoreq. x < 0.26 and 0.18. ltoreq. y < 0.29, and is not included in the backlight unit of A or B.

D: other backlight units.

The results are shown in tables 1 to 3.

[ Table 1]

[ Table 2]

[ Table 3]

From the results shown in tables 1 to 3, it is understood that the examples of the present invention have high color reproducibility of white light compared to the comparative examples.

The effects of the present invention are clear from the above results.

Description of the symbols

1-wavelength converting member, 10, 20-substrate film, 30-wavelength converting layer, 31-phosphor, 33-binder, 35-fluorescent region, 38-resin layer, 100-wavelength converting member, 101A-light source, 101B-light guide plate, 101C-planar light source, 102-backlight unit, 102A-reflector plate, 102B-retroreflective member.

Claims

1. A wavelength conversion member which absorbs at least a part of incident excitation light, converts the absorbed excitation light into light having a wavelength different from that of the excitation light, and emits the converted light,

the wavelength conversion member has a wavelength conversion layer having: a resin layer having a plurality of recesses discretely arranged on one main surface side; and a plurality of fluorescent regions including a phosphor, which are arranged in the concave portion formed on the resin layer,

the surface roughness Ra of the side surface of the concave part of the resin layer, which is from the fluorescent scattering of the fluorescent body, is 0.3 to 5 μm,

the difference Δ n between the refractive indices of the resin layer and the fluorescent region is 0.05 or more.

2. The wavelength converting member according to claim 1,

at least one of the resin layer and the fluorescent region includes scattering particles.

3. The wavelength converting member according to claim 1 or 2,

the depth of the recess formed in the resin layer is 1 to 150 [ mu ] m.

4. The wavelength converting member according to claim 1 or 2,

the width of the recess formed in the resin layer is 10 to 2000 [ mu ] m.

5. The wavelength converting member according to claim 1 or 2,

The wavelength conversion layer has two or more kinds of the fluorescent regions emitting light in different wavelength ranges.

6. The wavelength conversion member according to claim 1 or 2, which has two substrate films laminated with the wavelength conversion layer interposed therebetween.

7. The wavelength converting member according to claim 1 or 2,

the thickness of the wavelength conversion layer is 5-150 μm.

8. A backlight unit, having:

the wavelength converting member of any one of claims 1 to 7; and

a light source for emitting the excitation light.